If for some α,β\alpha, \beta; α≤β\alpha \leq \beta, α+β=8\alpha + \beta = 8 and sec⁡2(tan⁡−1α)+csc⁡2(cot⁡−1β)=36\sec^2(\tan^{-1} \alpha) + \csc^2(\cot^{-1} \beta) = 36, then α2+β\alpha^2 + \beta is

Answer: 14

Step-by-step solution

Step 1: Simplify the trigonometric expression

We use the identities sec⁡2x=1+tan⁡2x\sec^2 x = 1 + \tan^2 x and csc⁡2x=1+cot⁡2x\csc^2 x = 1 + \cot^2 x. Let x=tan⁡−1αx = \tan^{-1} \alpha and y=cot⁡−1βy = \cot^{-1} \beta. Then tan⁡x=α\tan x = \alpha and cot⁡y=β\cot y = \beta. Substituting these into the given equation simplifies the expression.

Step 2: Substitute and simplify

After applying the identities, we substitute tan⁡(tan⁡−1α)=α\tan(\tan^{-1} \alpha) = \alpha and cot⁡(cot⁡−1β)=β\cot(\cot^{-1} \beta) = \beta. This leads to a simplified algebraic equation involving α2\alpha^2 and β2\beta^2.

Step 3: Use the sum of roots identity

We are given α+β=8\alpha + \beta = 8 and we found α2+β2=34\alpha^2 + \beta^2 = 34. We can use the algebraic identity for the square of a sum to find the product αβ\alpha\beta.

Step 4: Calculate the product αβ\alpha\beta

Substitute the known values into the identity. This allows us to solve for 2αβ2\alpha\beta and then for αβ\alpha\beta.

Step 5: Form a quadratic equation for α\alpha and β\beta

We can form a quadratic equation whose roots are α\alpha and β\beta using the sum and product of the roots. The general form is x2−(sum of roots)x+(product of roots)=0x^2 - (\text{sum of roots})x + (\text{product of roots}) = 0.

Step 6: Solve the quadratic equation

Factor the quadratic equation to find the possible values for xx. These values represent α\alpha and β\beta.

Step 7: Determine α\alpha and β\beta and calculate α2+β\alpha^2 + \beta

Since it is given that α≤β\alpha \leq \beta, we assign α=3\alpha = 3 and β=5\beta = 5. Finally, we calculate the required expression α2+β\alpha^2 + \beta.

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