Trigonometry Answers

if sinX*cosY=1/4and 3tanX=4tanY then sin(X-Y)=

if tan40+2tan10=cotA then A=

if 2tanA+cotA=tanB then cotA+2tan(A-B)=

if A+B+C=180, prove that, asin(B-C)+bsin(C-A)+csin(A-B)=0.

prove cosx-sinx/cosx+sinx = sec2x-tan2x

A tree x m high the angle of elevation of its top from a point P on the ground is 23. from another point Q, 10 m from P and in line with P and the foot of the tree, the angle of elevation is 32. Find x.

In a cyclic quadrilateral ABCD PROve that sin(a/2) =cos(b/2)

Find the exact value by using a half-angle identity.

cosine of five pi divided by twelve.

Write the expression as either the sine, cosine, or tangent of a single angle.

cosine of pi divided by three times cosine of pi divided by five plus sine of pi divided by three times sine of pi divided by five.

In ∆ABC, A = 20, B = 80, C = 80. D lies on AC such that angle DBC = 70. E lies on AB such that ECB = 50. Using Trigonometric Version of Ceva's Theorem deduce that angle BDE = 10. All measures are in degree.