If f(x)=asinx+bcosx, a and b are positive real numbers, and f(x) is strictly increasing when x∈[0,π4)∪(5π4,2π] and it is strictly decreasing when x∈(π4,5π4), then the value of limθ→0(1−cosaθ)cot(bθ4)bθ is equal to

If f(x)=asinx+bcosx, a and b are positive real numbers, and f(x) is st

1.	If f(x)=asinx+bcosx, a and b are positive real numbers, and f(x) is strictly increasing when x∈[0,π4)∪(5π4,2π] and it is strictly decreasing when x∈(π4,5π4), then the value of limθ→0(1−cosaθ)cot(bθ4)bθ is equal to
Answer» If $f (x) = a sin x + b cos x, a$ and $b$ are positive real numbers, and $f (x)$ is strictly increasing when $x \in [0, \frac{π}{4}) \cup (\frac{5 π}{4}, 2 π]$ and it is strictly decreasing when $x \in (\frac{π}{4}, \frac{5 π}{4}),$ then the value of $lim θ \to 0 \frac{(1 - cos a θ) cot (\frac{b θ}{4})}{b θ}$ is equal to