The function `f(x)=(lambdasinx+2cosx)/(sinx+cosx)` is increasing, if (a) `lambda<1` (b) `lambda>1` (c) `lambda<2` (d) `lambda>2`

Explanation

`f(x)=frac{lambda sin x+2 cos x}{sin x+cos x}`


for increasing
`

f^{prime}(x)>0`
`


Rightarrow frac{(sin x+cos x)(lambda cos x-2 sin x)-(lambda sin x+2 cos x)(cos x-sin x)}{(sin x+cos x)^{2}}>0`
`
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