NDA Math Application of Derivatives

For f(x)=sin‌x,f(x)=cos‌x, which is always positive in the interval (0,‌

π

2

),
Hence the function f(x)=sin‌x is always increasing in the interval (0,‌

π

2

)
For f(x)=cos‌x,f(x)=−sin‌x, which is always negative in the interval (0,‌

π

2

),
Hence the function f(x)=cos‌x is always decreasing in the interval (0,‌

π

2

)