Posted by **Anonymous** on Monday, February 20, 2012 at 10:22pm.

Simplify #3:

[cosx-sin(90-x)sinx]/[cosx-cos(180-x)tanx]

= [cosx-(sin90cosx-cos90sinx)sinx]/[cosx-(cos180cosx+sinx180sinx)tanx]

= [cosx-((1)cosx-(0)sinx)sinx]/[cosx-((-1)cosx+(0)sinx)tanx]

= [cosx-cosxsinx]/[cosx+cosxtanx]

= [cosx(1-sinx]/[cosx(1+tanx]

= (1-sinx)/(1+tanx)

Is this correct???

- Trigonometry Check -
**Steve**, Tuesday, February 21, 2012 at 11:31am
looks good to me

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