Mathematics : asked on zitlays
 22.01.2022

Given f(x)=3x+1, solve for x when f(x)=7.

. 4

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Mathematics
Step-by-step answer
P Answered by PhD

x = -2

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Equality Properties

Algebra I

Function Notation

Step-by-step explanation:

Step 1: Define

f(x) = 3x - 1

f(x) = -7

Step 2: Solve for x

Substitute:                    -7 = 3x - 1Isolate x term:              -6 = 3xIsolate x:                       -2 = xRewrite:                        x = -2
Mathematics
Step-by-step answer
P Answered by Master

{ \tt{f(x) = 3x + 1}}

• when f(x) is 7,

{ \tt{3x + 1 = 7}} \\  \\ { \tt{3x = 6}} \\  \\ { \tt{x =  \frac{6}{3} }} \\  \\ { \boxed{ \rm{ \: x = 2 \: }}}

Mathematics
Step-by-step answer
P Answered by PhD

x = -2

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Equality Properties

Algebra I

Function Notation

Step-by-step explanation:

Step 1: Define

f(x) = 3x - 1

f(x) = -7

Step 2: Solve for x

Substitute:                    -7 = 3x - 1Isolate x term:              -6 = 3xIsolate x:                       -2 = xRewrite:                        x = -2
Mathematics
Step-by-step answer
P Answered by PhD

f(7) = 22

Step-by-step explanation:

1. f(x) = 3x + 1

2. f(7) = 3(7) + 1

3. f(7) = 21 + 1

Mathematics
Step-by-step answer
P Answered by PhD

x = 2

Step-by-step explanation:

Step 1: Define

f(x) = 3x + 1

f(x) = 7

Step 2: Substitute

7 = 3x + 1

Step 3: Solve for x

6 = 3x

x = 2

Mathematics
Step-by-step answer
P Answered by Master

1. f(x) = 1/4x − 1. B)The line will be less steep. The slope is lower now

2. C)x-intercept (−1/3 , 0). Replacing f(x) = 0 we get x = -1/3

3. B)horizontal line with a slope of zero. The slope is 0 because there is no x in the equation.

4. D)Line changes from decreasing to increasing. The slope changed from negative to positive.

5. See first graph attached

6. See second graph attached. g(x) = (1/3)*x

7. C)The rate of change is different, but the y-intercepts are the same. The rate of change of Mike is negative because he withdraws $25 each week. The y-intercepts of Mike is $200 because that was his initial deposit.

8.  B)shifts the line 7 units down. f(x-7) translates f(x) 7 units to the right, given the slope is positive ( = 1) then f(x) is translated 7 units down.

9. No graph is shown

10. C)g(x) = x - 3. g(x) = f(x) - 3, so g(x) is f(x) translated 3 units down.


Test due 12/1 the function f(x) = x − 1 is changed to f(x) = 1 4 x − 1. which describes the effect o
Test due 12/1 the function f(x) = x − 1 is changed to f(x) = 1 4 x − 1. which describes the effect o
Mathematics
Step-by-step answer
P Answered by Specialist

1. f(x) = 1/4x − 1. B)The line will be less steep. The slope is lower now

2. C)x-intercept (−1/3 , 0). Replacing f(x) = 0 we get x = -1/3

3. B)horizontal line with a slope of zero. The slope is 0 because there is no x in the equation.

4. D)Line changes from decreasing to increasing. The slope changed from negative to positive.

5. See first graph attached

6. See second graph attached. g(x) = (1/3)*x

7. C)The rate of change is different, but the y-intercepts are the same. The rate of change of Mike is negative because he withdraws $25 each week. The y-intercepts of Mike is $200 because that was his initial deposit.

8.  B)shifts the line 7 units down. f(x-7) translates f(x) 7 units to the right, given the slope is positive ( = 1) then f(x) is translated 7 units down.

9. No graph is shown

10. C)g(x) = x - 3. g(x) = f(x) - 3, so g(x) is f(x) translated 3 units down.


Test due 12/1 the function f(x) = x − 1 is changed to f(x) = 1 4 x − 1. which describes the effect o
Test due 12/1 the function f(x) = x − 1 is changed to f(x) = 1 4 x − 1. which describes the effect o
Mathematics
Step-by-step answer
P Answered by PhD
#1
Factoring the function:
f(x) = x3 + 7x2 + 14x + 8
f(x) = (x + 4) (x + 1) (x + 2)

From the options, (x + 2) is the factor

#2
f(x) / g(x) = (6x3 - 19x2 + 16x - 4) / (x - 2)
This can be solved by factoring the numerator, by synthetic division or using the remainder theorem.

The result is:
6x^2 - 7x + 2 or (x - 2/3)(x - 1/2)
 
#3 same with #2

#4
(x3 - 5x2 + 2x + 5) / (x - 2)
Again, this can be solved by a number of methods, the result is:
x2 -3x - 4 - (3/x-2)
Mathematics
Step-by-step answer
P Answered by PhD
#1
Factoring the function:
f(x) = x3 + 7x2 + 14x + 8
f(x) = (x + 4) (x + 1) (x + 2)

From the options, (x + 2) is the factor

#2
f(x) / g(x) = (6x3 - 19x2 + 16x - 4) / (x - 2)
This can be solved by factoring the numerator, by synthetic division or using the remainder theorem.

The result is:
6x^2 - 7x + 2 or (x - 2/3)(x - 1/2)
 
#3 same with #2

#4
(x3 - 5x2 + 2x + 5) / (x - 2)
Again, this can be solved by a number of methods, the result is:
x2 -3x - 4 - (3/x-2)
Mathematics
Step-by-step answer
P Answered by Master
1. Ans:(A) 123

Given function: f(x) = 8x^2 + 11x
The derivative would be:
\frac{d}{dx} f(x) = \frac{d}{dx}(8x^2 + 11x)
=> \frac{d}{dx} f(x) = \frac{d}{dx}(8x^2) + \frac{d}{dx}(11x)
=> \frac{d}{dx} f(x) = 2*8(x^{2-1}) + 11
=> \frac{d}{dx} f(x) = 16x + 11

Now at x = 7:
\frac{d}{dx} f(7) = 16(7) + 11

=> \frac{d}{dx} f(7) = 123

2. Ans:(B) 3

Given function: f(x) =3x + 8
The derivative would be:
\frac{d}{dx} f(x) = \frac{d}{dx}(3x + 8)
=> \frac{d}{dx} f(x) = \frac{d}{dx}(3x) + \frac{d}{dx}(8)
=> \frac{d}{dx} f(x) = 3*1 + 0
=> \frac{d}{dx} f(x) = 3

Now at x = 4:
\frac{d}{dx} f(4) = 3 (as constant)

=>Ans:  \frac{d}{dx} f(4) = 3

3. Ans:(D) -5

Given function: f(x) = \frac{5}{x}
The derivative would be:
\frac{d}{dx} f(x) = \frac{d}{dx}(\frac{5}{x})
or 
\frac{d}{dx} f(x) = \frac{d}{dx}(5x^{-1})
=> \frac{d}{dx} f(x) = 5*(-1)*(x^{-1-1})
=> \frac{d}{dx} f(x) = -5x^{-2}

Now at x = -1:
\frac{d}{dx} f(-1) = -5(-1)^{-2}

=> \frac{d}{dx} f(-1) = -5 *\frac{1}{(-1)^{2}}
=> Ans: \frac{d}{dx} f(-1) = -5

4. Ans:(C) 7 divided by 9

Given function: f(x) = \frac{-7}{x}
The derivative would be:
\frac{d}{dx} f(x) = \frac{d}{dx}(\frac{-7}{x})
or 
\frac{d}{dx} f(x) = \frac{d}{dx}(-7x^{-1})
=> \frac{d}{dx} f(x) = -7*(-1)*(x^{-1-1})
=> \frac{d}{dx} f(x) = 7x^{-2}

Now at x = -3:
\frac{d}{dx} f(-3) = 7(-3)^{-2}

=> \frac{d}{dx} f(-3) = 7 *\frac{1}{(-3)^{2}}
=> Ans: \frac{d}{dx} f(-3) = \frac{7}{9}

5. Ans:(C) -8

Given function: 
f(x) = x^2 - 8

Now if we apply limit:
\lim_{x \to 0} f(x) = \lim_{x \to 0} (x^2 - 8)

=> \lim_{x \to 0} f(x) = (0)^2 - 8
=> Ans: \lim_{x \to 0} f(x) = - 8

6. Ans:(C) 9

Given function: 
f(x) = x^2 + 3x - 1

Now if we apply limit:
\lim_{x \to 2} f(x) = \lim_{x \to 2} (x^2 + 3x - 1)

=> \lim_{x \to 2} f(x) = (2)^2 + 3(2) - 1
=> Ans: \lim_{x \to 2} f(x) = 4 + 6 - 1 = 9

7. Ans:(D) doesn't exist.

Given function: f(x) = -6 + \frac{x}{x^4}
In this case, even if we try to simplify it algebraically, there would ALWAYS be x power something (positive) in the denominator. And when we apply the limit approaches to 0, it would always be either + infinity or -infinity. Hence, Limit doesn't exist.

Check:
f(x) = -6 + \frac{x}{x^4} \\ f(x) = -6 + \frac{1}{x^3} \\ f(x) = \frac{-6x^3 + 1}{x^3} \\ Rationalize: \\ f(x) = \frac{-6x^3 + 1}{x^3} * \frac{x^{-3}}{x^{-3}} \\ f(x) = \frac{-6x^{3-3} + x^{-3}}{x^0} \\ f(x) = -6 + \frac{1}{x^3} \\ Same

If you apply the limit, answer would be infinity.

8. Ans:(A) Doesn't Exist.

Given function: f(x) = 9 + \frac{x}{x^3}
Same as Question 7
If we try to simplify it algebraically, there would ALWAYS be x power something (positive) in the denominator. And when we apply the limit approaches to 0, it would always be either + infinity or -infinity. Hence, Limit doesn't exist.

9, 10.
Please attach the graphs. I shall amend the answer. :)

11. Ans:(A) Doesn't exist.

First We need to find out: \lim_{x \to 9} f(x) where,
f(x) = \left \{ {{x+9, ~~~~~x \textless 9} \atop {9- x,~~~~~x \geq 9}} \right.

If both sides are equal on applying limit then limit does exist.

Let check:
If x \textless 9: answer would be 9+9 = 18
If x \geq 9: answer would be 9-9 = 0

Since both are not equal, as 18 \neq 0, hence limit doesn't exist.

12. Ans:(B) Limit doesn't exist.

Find out: \lim_{x \to 1} f(x) where,

f(x) = \left \{ {{1-x, ~~~~~x \textless 1} \atop {x+7,~~~~~x \textgreater 1} } \right. \\ and \\ f(x) = 8, ~~~~~ x=1

If all of above three are equal upon applying limit, then limit exists.

When x < 1 -> 1-1 = 0
When x = 1 -> 8
When x > 1 -> 7 + 1 = 8

ALL of the THREE must be equal. As they are not equal. 0 \neq 8; hence, limit doesn't exist.

13. Ans:(D) -∞; x = 9

f(x) = 1/(x-9).

Table:

x                      f(x)=1/(x-9)       

----------------------------------------

8.9                       -10

8.99                     -100

8.999                   -1000

8.9999                 -10000

9.0                        -∞


Below the graph is attached! As you can see in the graph that at x=9, the curve approaches but NEVER exactly touches the x=9 line. Also the curve is in downward direction when you approach from the left. Hence, -∞,  x =9 (correct)

 14. Ans: -6

s(t) = -2 - 6t

Inst. velocity = \frac{ds(t)}{dt}

Therefore,

\frac{ds(t)}{dt} = \frac{ds(t)}{dt}(-2-6t) \\ \frac{ds(t)}{dt} = 0 - 6 = -6

At t=2,

Inst. velocity = -6


15. Ans: +∞,  x =7 

f(x) = 1/(x-7)^2.

Table:

x              f(x)= 1/(x-7)^2     

--------------------------

6.9             +100

6.99           +10000

6.999         +1000000

6.9999       +100000000

7.0              +∞

Below the graph is attached! As you can see in the graph that at x=7, the curve approaches but NEVER exactly touches the x=7 line. The curve is in upward direction if approached from left or right. Hence, +∞,  x =7 (correct)

-i


Good answers get brainliest. +40 points wrong answers get reported 9.05a 1. find the derivative of f
Good answers get brainliest. +40 points wrong answers get reported 9.05a 1. find the derivative of f

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