graphs!!

i m trying to learn to draw graphs , and i m facing a few problems with it.
we kno how to draw graph of a quadratic , and we can also draw graph of a few simple trigo functions
but when there is a situation such that the function is a quadratic of sinx , then shud be the approach ??

for eg: y=sin^{2}x+sinx+1

also if there is a quadratic of the form y=t^{2}+t+1

where t=x-\frac{1}{x}

wat shud be de approach ???