Question 6.6.4.8: Establishing an identity Establish the identity: 1-sin θ/cos......

Start with the left side and multiply the numerator and the denominator by 1\,+\, \sin \theta. (Alternatively, we could multiply the numerator and the denominator of the right side by 1\,-\,\sin \theta.)

{\frac{1-\sin\theta}{\cos\theta}}={\frac{1-\sin\theta}{\cos\theta}}\cdot{\frac{1+\sin\theta}{1+\sin\theta}}         Multiply the numerator and the denominator by

={\frac{\cos \theta}{1+\sin\theta}}          Divide out