一个P Calculus AB : Tangent line to a curve at a point and local linear approximation

年代tudy concepts, example questions & explanations for AP Calculus AB

varsity tutors app store varsity tutors android store

Example Questions

← Previous 1

Example Question #1 :Derivatives

Differentiate,

Possible Answers:

Correct answer:

Explanation:

Differentiate,

年代trategy

This one at first glance appears difficult even if we recognize that the chain rule is needed; we have a function within a function within a function within a function. To avoid making mistakes, it's best to start by defining variables to make the calculation easier to follow.

Let's start with the outermost function, we will writeas a function ofby setting,

______________________________________________________

_______________________________________________________

年代imilarly, defineto writeas a function of

_______________________________________________________

Writeas a function of

_______________________________________________________

Finally, define the inner-most function,, as the function of

________________________________________________________

年代incewe will just substitute that in and move to the front.

That was easy enough, now just write everything in terms ofby going back to the definitions of.

Example Question #1 :一个p Calculus Ab

Find the tangent line. Given the point (1,2)

Possible Answers:

Correct answer:

Explanation:

To find the tangent line at the given point, we need to first take the derivative of the given function.

Power Rule:

Power rule says that we take the exponent of the “x” value and bring it to the front. Then we subtract one from the exponent.

Therefore,becomes

From there we plug in the "1" from the point to get our m value of the equation. When we plug in "1" to y' we get m=-1. Then from there, we will plug our point intonow that we have found m to find our b value. So,

Therefore, the tangent line is equal to

Example Question #3 :Derivatives

Find the line tangent at the point (0,1)

Possible Answers:

Correct answer:

Explanation:

To find the tangent line at the given point, we need to first take the derivative of the given function. The rule for functions with "e" in it says that the derivative ofHowever with this function there is also a 3 in the exponent so we will also use chain rule. Chain Rules states that we work from the outside to the inside. Meaning we will take the derivative of the outside of the equation and multiply it by the derivative of the inside of the equation.

To put this into equation it will look like

From there we plug in the "0" from the point to get our m value of the equation . When we plug in "0" to y' we get m=3. Then from there, we will plug our point intonow that we have found m to find our m value. So,

then plug this all back into the equation once more and we are left with

Example Question #4 :Derivatives

Find the tangent line given the point (2,4) and the equation

Possible Answers:

Correct answer:

Explanation:

To find the tangent line at the given point, we need to first take the derivative of the given function using Power Rule

Power rule says that we take the exponent of the “x” value and bring it to the front. Then we subtract one from the exponent.

From there we plug in the "2" from the point to get our m value of the equation . When we plug in "2" to y' we get m=8. Then from there, we will plug our point into now that we have found m to find our b value. So,

Plug this back into

Example Question #5 :Derivatives

Find the equation of the line tangent to the curve at the point where

Possible Answers:

Correct answer:

Explanation:

Find the equation of the line tangent to the curveat the given point

The slope of the line tangent at the given point will be equal to the derivative ofat that point. Compute the derivative and find the slope for our line:

Evaluate the secant term:

Therefore slope of the tangent line is simply:

年代o now we know the slope of the tangent line and can write the equation then solve for

In order to solve forwe need one point on the line. Use the point where the tangent line meets the curve. Use the original function to find the "y" coordinate at this point:

We now have our point:

Use the point to find

Example Question #6 :Derivatives

Find the slope of the line tangent to the curve of d(g) when g=6.

Possible Answers:

Correct answer:

Explanation:

Find the slope of the line tangent to the curve of d(g) when g=6.

一个ll we need here is the power rule. This states that to find the derivative of a polynomial, simply subtract 1 from each exponent and then multiply each term by their original exponent.

Constant terms will drop out when we do this, and linear terms will become constants.

From here substitute in g=6.

Example Question #7 :Derivatives

Give the equation of the line tangent to the graph of the equation

at the point.

Possible Answers:

Correct answer:

Explanation:

The tangent line to the graph ofat pointis the line with slopethat passes through that point. Find the derivative:

一个pply the sum rule:

The tangent line is therefore the line with slope 5 through.Apply the point-slope formula:

Example Question #8 :Derivatives

Give the equation of the line tangent to the graph of the equation

at the point.

Possible Answers:

None of the other choices gives the correct response.

Correct answer:

None of the other choices gives the correct response.

Explanation:

The tangent line to the graph ofat pointis the line with slopethat passes through that point. Find the derivative:

一个pply the constant multiple and sum rules:

年代et和apply the chain rule.

年代ubstituting back:

Evaluateusing substitution:

The tangent line is therefore the line with slopethrough.is a-intercept, so apply the slope-intercept formula to get the equation

.

This is not among the choices given.

Example Question #9 :Derivatives

Find the equation of the line parallel to the functionat, and passes through the point

Possible Answers:

Correct answer:

Explanation:

We first start by finding the slope of the line in question, which we do by taking the derivative of和evaluate at.

,

We then use point slope form to get the equation of the line at the point

Example Question #10 :Derivatives

Find the equation of the line tangent toat the point.

Possible Answers:

Correct answer:

Explanation:

The first step is to find the derivative of the function given, which is. Next, find the slope at (1,4) by plugging in x=1 and solving for, which is the slope. You should get. This means the slope of the new line is also -1 because at the point where a slope and a line are tangent they have the same slope. Use the equationto express your line. Y and x are variables and m is the slope, so the only thing you need to find is b. Plug in the point and slope intoto get. Now you can express the general equation of the line as.

← Previous 1
Learning Tools by Varsity Tutors