Question
If θ is an acute angle and sin θ + cosec θ = 2, then
the value of sin2 θ + cosec2 θ is:Solution
Given – sin + cseccθ = 2, let x = sin θ, then cosec θ =1/x ATQ- x+1/x =2  x²+1 = 2x x²-2x+1 0 (x-1)2 = 0 x-1 =0 x =1. Thus, sin θ = 1, which means θ = 90°. Now, Sin 2 θ = 15=1 Similarly, Cosec2 θ = 1 Therefore, Sin 2 θ + Cosec2 θ =1+1=2 So, the value is 2.
40% of 220 × 15 ÷ 20 = ?
What will come in the place of question mark (?) in the given expression?
7 X 18 + ? = (52 - 6) X 9
192.251 + 326.233 + 125.021 + 19.273 = ?
What will come in place of the question mark (?) in the following expression?
18 × 16 – 11 × 4 = 15² + ?
- What will come in place of (?) in the given expression.
48 ÷ 4 × 5 + 36 – 18 = ? - What will come in the place of question mark (?) in the given expression?
1231 + 1312 + 2113 – 3211 = ? 721 +21 x 9 - 118 = ? + 82
- What will come in place of the question mark (?) in the following questions?
0.5×120+25=? I. x² + 3x – 154 = 0
II. y² + 5y – 126 = 0