Tangent Lines - GMAT Quantitative

Card 1 of 96

0
Didn't Know
Knew It
0
1 of 2019 left
Question

Determine the equation of the line tangent to the curve at the point ?

Tap to reveal answer

Answer

To find the equation of a line tangent to a curve at a certain point, we first need to find the slope of the curve at that point. To find the slope of a function at any point, we need its derivative:

Now we can plug in the x value of the given point to find the slope of the function, and therefore the slope of tangent line, at that point:

Now that we have our slope, we can simply plug this value in with the given point to solve for the y intercept of the tangent line:

We have calculated the slope of the tangent line and its y intercept, so the equation for the line tangent to the curve at the point in standard form is:

← Didn't Know|Knew It →