Originally Posted bykennysbaby28

solved....

(tan[theta] + cot[theta])^2=

=(tan[theta])^2 +2(tan[theta]) ( cot[theta]) +(cot[theta])^2

=(tan[theta])^2 +2(sin[theta]/cos[theta])(cos[theta]/sine[theta]+(cot[theta])^2

=(tan[theta])^2 +2+(cot[theta])^2

={(tan[theta])^2 +1}+{(cot[theta])^2+1}

an we know

(tan[theta])^2 +1=sec^2[theta] and

(cot[theta])^2 +1=csc^2[theta]

then

(tan[theta] + cot[theta])^2=sec^2[theta] + csc^2[theta]