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View Full Version : How would you prove cot theta + (sin theta/1+cos theta)= csc theta ?


chambawi
Aug 26, 2010, 06:40 PM
This is a seatwork in my trigonometry subject. Please help

Unknown008
Aug 27, 2010, 08:36 AM
cot\theta + \frac{sin\theta}{1+cos\theta}

Convert everything to cos and sin.

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

Combine to form a single fraction:

= \frac{cos\theta(1+cos\theta) + sin^2\theta}{sin\theta(1+cos\theta)}

Sinplify:

= \frac{cos\theta + cos^2 \theta + sin^2\theta}{sin\theta(1+cos\theta)}

Now, cos^2theta + sin^2theta = 1. So,

= \frac{cos\theta + 1}{sin\theta(1+cos\theta)}

Can you complete it now? :)