Question

If $0<\theta <\frac{\pi }{4}$ , then $(\cos \theta -\sin \theta )$ is

• A. always negative
• B. always positive
• C. sometimes positive and sometimes negative
• D. zero

Answer 1

The correct option is B always positive

Consider the given expression,

If $0<\theta <\frac{\pi }{4}$ , then $\cos \theta -\sin \theta$.

Now,

We know that $cos\theta >\sin \theta$ if $0<\theta <\frac{\pi }{4}$

Hence,$\cos \theta -\sin \theta >0$ if $0<\theta <\frac{\pi }{4}$

Hence, this is the answer.