Find the absolute maximum value and the absolute minimum value of `f(x)=sinx+cosx` in `[0,\ pi]`

Explanation

`{f}({x})=sin {x}+cos {x}`

`f^{prime}(x)=cos x-sin x`

Put `f^{prime}(x)=0`,

`cos x-sin x=0 `


`cos x=sin x `

`tan x=1 `

`x=tan ^{-1}(1)`

`x=frac{pi}{4}`

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