about to only mathematics

Options

A. `1`
B. 2
C. 3
D. none of these

Answer

A

Explanation

Since f(x) is periodic with period `(pi)/(2)` .
`:. f(x+(pi)/(2))=f(x) ` for all x
`implies lambda|cosx|+lambda^(2)| sin x| +phi (lambda )= lambda|sin x|+lambda^(2)|cosx| + phi (lambda )` for all x
`implies ( lambda-lambda^(2))(|cosx|-|sinx|)=0` for all x
`implies lambda-lambda^(2)=0implies 1 " " [ :' lambda ne 0]`