If cos θ = 2/3, write the value of (4 +4 tan2 θ).

Give: cos θ = 2/3Therefore sec θ = 1/cos θ= 3/2Consider 4 tan2 θ + 4 = 4 (tan2 θ + 1)= 4 sec2 θ (∵ 1 + tan2 θ = sec2 θ)= 4 (3/2)2= 4 × (9/4)= 9

Q17 of 186 Page 345

If cos θ = 2/3, write the value of (4 +4 tan² θ).

Give: cos θ = 2/3

Therefore sec θ = 1/cos θ

= 3/2

Consider 4 tan² θ + 4 = 4 (tan² θ + 1)

= 4 sec² θ (∵ 1 + tan² θ = sec² θ)

= 4 (3/2)²

= 4 × (9/4)

= 9

Write the value of

If sin θ = 1/2, write the value of (3 cot² θ + 3).

If cos θ = 7/25, write the value of (tan θ + cot θ).

If cos θ = 2/3, write the value of .