Trigonometry Answers

Without using tables,find the value of sin260+cos 260

A 2
B 5
C 1
D 2

Deduce the identity of :
1+tan2θ

A secθ

B sinθ

C cosθ

D sec2θ

Deduce the identity of :
1−2sin2A

A sin 2A
B tan 2A
C cos 2A
D cos A

Without using tables, find the value of tan 450

A 3
B 5
C 2
D 1

Deduce the identity of : (tanA)(cotA)

A 0
B 90
C 1
D 45

Solve triangle ABC which has angleA=250.251,angleB=600.511anda=3.82.Find c.

A 3-6cm
B 7.0cm
C 7.4cm
D 8.8cm

Solve the following equation:
4sin^2 (x) +7cos(x) = 6

Hexagon ABCDEF is inscribed in the circle with centre M and radius R. AB=CD=EF=R. Points I, J and K are the midpoints of segments BC, DE and FA respectively. Prove that triangle IJK is equilateral.

Note: Could you please use trigonometry? The method is to find MI and MJ, and then use cosine rule in triangle MIJ to find IJ. Then simplify the expression obtained for IJ, and as it will be symmetrical, the triangle will be equilateral.