For part of my parametric eqn i need to differentiate 3-2cos2 theta, when i do this i get 2-sin2 theta, but the answers says 4sin2 theta, what am i doing wrong(Wondering)

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- Mar 18th 2012, 06:52 AMjohnrealDifferentiating with parametric equations
For part of my parametric eqn i need to differentiate 3-2cos2 theta, when i do this i get 2-sin2 theta, but the answers says 4sin2 theta, what am i doing wrong(Wondering)

- Mar 18th 2012, 06:58 AMprincepsRe: Differentiating with parametric equations
- Mar 18th 2012, 07:18 AMjohnrealRe: Differentiating with parametric equations
Thanks alot this helped *slaps face* Product Rule, ive worked out most of it and ive reached sin2 theta/cos theta, i did that by having 4sin2 theta/4cos theta and cancelling the fours, im supposed to get 2 sin theta, did i do some thing wrong?

- Mar 18th 2012, 07:27 AMprincepsRe: Differentiating with parametric equations