Determine the number of zeros of $\displaystyle f$ in the first quadrant.

(1) $\displaystyle f(z)=z^4-3z^2+3$

(2) $\displaystyle f(z)=z^2+iz+2+i$

(3) $\displaystyle f(z) = z^7+6z^3+7$

I really can't follow along in the book of how they do this. I was wondering if there was a simpler way of figuring out these problems. Any help would be appreciated, thanks!