Applications Of Derivatives Question 354
Question: The function $ y=a(1-\cos x) $ is maximum when $ x= $
[Kerala (Engg.) 2002]
Options:
A) $ \pi $
B) $ \pi /2 $
C) $ -\pi /2 $
D) $ -\pi /6 $
Show Answer
Answer:
Correct Answer: A
Solution:
$ y=a,(1-\cos x) $
therefore $ {y}’=a\sin x $
therefore $ {y}’=0\Rightarrow \sin x=0 $
therefore $ x=0,,\pi $ Now $ {y}’’=a\cos x $
therefore $ {y}’’(0)=a $ and $ {y}’’(\pi )=-a $
Hence y is maximum when $ x=\pi $ .
BETA
