Question
Evaluate: 1 + tan²(cos⁻¹x)
Solution
We are given the expression: 1 + tan²(cos⁻¹x) Recall the trigonometric identity: 1 + tan²θ = sec²θ So, 1 + tan²(cos⁻¹x) = sec²(cos⁻¹x) Now use the identity: sec(cos⁻¹x) = 1 / x (since cos⁻¹x gives an angle whose cosine is x) Therefore: sec²(cos⁻¹x) = (1/x)² = 1/x²
3, 5, 12, 38, 154, ?
What will come in place of the question mark (?) in the following series?
132, 101, 130, ?, 126, 109
12, 24, 46, 78, 120, ?
25 25 37.5 ? 328.125 1804.6875
124, 128, ?, 135, 110, 146
155, 157, 160, ?, 172, 183
22, 37, 63, 98, 148, ?
What will come in place of the question mark (?) in the following series?
1.5, 3.5, 9.5, 27.5, 81.5, 243.5, ?
72, 82, 62, 102, 22, ?
5, 6, 14, 45, ?, 925