100
The 3 main pythagorean identities, the quotient identities, and the reciprical identities.
What is sin^2x+cos^2x=1; tan^2+1=sec^2x; 1+cot^2=csc^2x; tanx=sinx/cosx; cot=cosx/sinx; cosx=1/secx; sinx=1/cscx; tanx=1/cotx; secx=1/cosx; cscx=1/sinx; cotx=1/tanx