ABSTRACT
Solve the triangle and determine its area. (10)
2. Figure R7.2 shows a roof truss PQR with rafter PQ = 3 m. Calculate the length of (a) the roof rise PP′, (b) rafter PR, and (c) the roof span QR. Find also (d) the cross-sectional area of the roof truss. (11)
3. Prove the following identities:
(a) √
1 − cos2 θ cos2 θ
= tan θ
(b) cos (
3π 2
+ φ )
= sin φ (6)
4. Solve the following trigonometric equations in the range 0◦ ≤ x ≤ 360◦: (a) 4 cos x + 1 = 0 (b) 3.25 cosec x = 5.25 (c) 5 sin2 x + 3 sin x = 4 (13)
5. Solve the equation 5 sin(θ −π/6) = 8 cos θ for values 0 ≤ θ ≤ 2π (8)
6. Express 5.3 cos t − 7.2 sin t in the form R sin(t +α). Hence solve the equation 5.3 cos t − 7.2 sin t = 4.5 in the range 0 ≤ t ≤ 2π (12)
