Application Of Derivatives Ques 76
76. The number of values of $x$, where the function $f(x)=\cos x+\cos (\sqrt{2} x)$ attains its maximum, is(1998, 2M)
(a) 0
(b) 1
(c) 2
(d) infinite
Show Answer
Answer:
Correct Answer: 76.(b)
Solution:
Formula:
Maxima and Minima of functions of one variable :
- The maximum value of $f(x)=\cos x+\cos (\sqrt{2} x)$ is 2 which occurs at $x=0$. Also, there is no other value of $x$ for which this value will be attained again.
BETA
