Practicing Success
In a ΔABC right angled at B, AB = 8 unit and AC = 10 unit. What is the value of $\sin^2θ-\cos^2θ$ where θ is ∠ACB? |
$\frac{9}{25}$ $\frac{7}{25}$ $\frac{22}{25}$ $\frac{16}{25}$ |
$\frac{7}{25}$ |
In a ΔABC right angled at B, AB = 8 unit and AC = 10 unit AC^2 = AB^2 + BC^2 100 = 64 + BC^2 BC = 6 SinB = 8/10 = 4/5 Sin2B = 16/25 CosB = 6/10 = 3/5 Cos2B = 9/25 Sin2B - Cos2B = 16/25 - 9/25 = 7/25
The correct answer is Option (2) → $\frac{7}{25}$ |