Question

Proof cos square (90-theta) is equal to sin square theta

Answer 1

Step-by-step explanation:

We know that:

${cos}(90 \degree - \theta) = sin \theta\\ \therefore \: {cos} ^{2} (90 \degree - \theta) \\ = {cos}(90 \degree - \theta) \times {cos}(90 \degree - \theta) \\ = sin \theta \times sin \theta \\ = {sin }^{2} \theta \: \\ thus \\ \fbox { \red{{cos} ^{2} (90 \degree - \theta) = {sin }^{2} \theta}}$