Saturday

April 19, 2014

April 19, 2014

Posted by **Anonymous** on Wednesday, July 27, 2011 at 11:50am.

- maths -
**Reiny**, Wednesday, July 27, 2011 at 12:37pmDid you notice that in the first two terms the angles mentioned are complimentary angles?

And did you know that cos 70 = sin 20 ?

so....

cos70/sin20+cos57cosec33-2cos60

= cos70/sin20 + cos57/sin33 - 2cos60

= sin20/sin20 + cos57/cos57 - 2cos60

= 1+1 - 2(1/2)

= 1

**Related Questions**

math - how do i get sec70 x cos70 algebraically?

Trig - sin45cos25 + cos45sin25 = ?? a. cos70 b. sin70 c. cos20 d. sin 20 which ...

MATHS...... - solve the following. 1) x^3+3y^3+x+2y

Trig - Can someone check my answers so far? 1. Find the exact value of tan(-3ð) ...

Maths - Hey :) I'm sitting my maths non-calculator GCSE tomorrow and am ...

PLEASE ANSWER MATHS!!! - solve algebriaclly the equation y=2sin2x+1 for 0<_x_...

Trig - cos45cos25 - sin 45sin25 = ?? a. cos70 b. sin70 c. cos 20 d. sin 20 which...

physics - If a pulley is 57% efficient and you lift a 35kg box 5m how much work ...

Maths - solve the following pair of simultaneous equation: (x/a)+(y/b)=1 (x/b)+(...

math - Evaluate the following with thought the use of a calculator: Sin70.sin25...