Applications-Of-Derivatives Question 468

Question: The tangent drawn at the point (0, 1) on the curve $ y=e^{2x} $ meets x-axis at the point

[RPET 2002]

Options:

A) $ (1/2,,0) $

B) $ (-1/2,0) $

C) (2, 0)

D) $ (0,0) $

Show Answer

Answer:

Correct Answer: B

Solution:

$ y=e^{2x} $
Þ $ \frac{dy}{dx}=2e^{2x} $
Þ $ ( \frac{dy}{dx} )_{(0,,1)}^{{}}=2 $ \ Equation of tangent is, $ y-1=2(x-0)\Rightarrow y=2x+1 $ This tangent meets x-axis,
$ \therefore y=0 $
Þ $ 0=2x+1\Rightarrow x=-1/2 $ \ Co-ordinates of the point $ ( -\frac{1}{2},,0 ). $