If tan^-1 (sin^2 theta 2sin theta 2) cot^-1(4sec^2 phi 1)=pi/2 ha...
To solve the given equation, let's simplify it step by step:
Step 1: Simplify the expression inside the first inverse tangent (tan^-1).
tan^-1 (sin^2θ + 2sinθ + 2)
Step 2: Use the trigonometric identity sin^2θ + cos^2θ = 1.
sin^2θ + 2sinθ + 2 = 1 - cos^2θ + 2sinθ + 2
Step 3: Rearrange the terms.
cos^2θ - 2sinθ + 1 = 0
Step 4: Factorize the quadratic equation.
(cosθ - 1)(cosθ + 1) - 2sinθ = 0
Step 5: Simplify.
(cosθ - 1)(cosθ + 1) = 2sinθ
Step 6: Divide both sides by cosθ.
cosθ + 1 = 2sinθ / cosθ
Step 7: Use the trigonometric identity tanθ = sinθ / cosθ.
cosθ + 1 = 2tanθ
Step 8: Simplify.
2tanθ - cosθ - 1 = 0
Now, let's simplify the expression inside the second inverse cotangent (cot^-1).
cot^-1 (4sec^2φ + 1)
Step 1: Use the trigonometric identity sec^2φ = 1 + tan^2φ.
4(1 + tan^2φ) + 1
Step 2: Simplify.
4 + 4tan^2φ + 1
Step 3: Combine like terms.
5 + 4tan^2φ
Step 4: Use the trigonometric identity tan^2φ = sec^2φ - 1.
5 + 4(sec^2φ - 1)
Step 5: Simplify.
4sec^2φ + 1
Now, let's substitute the simplified expressions back into the original equation:
2tanθ - cosθ - 1 = cot^-1 (4sec^2φ + 1)
Since the equation is equal to π/2, we can rewrite it as:
2tanθ - cosθ - 1 = π/2
Now, let's analyze the options and determine which one(s) satisfy the equation:
A) sinθ = -1
If sinθ = -1, then tanθ = sinθ / cosθ = -1 / cosθ.
Substituting into the equation:
2(-1 / cosθ) - cosθ - 1 = π/2
This equation does not hold true for all values of cosθ, so option A is not a valid solution.
B) sinφ = 1
If sinφ = 1, then cosφ = √(1 - sin^2φ) = √(1 - 1) = 0.
Substituting into the equation:
2tanθ - cosθ - 1 = π/2
This equation does not hold true for all values of tanθ, so option B is not a valid solution.
C) cosθ = 1
If cosθ = 1, then tanθ = sinθ / cosθ = sinθ.
Substituting into the equation:
2sinθ - 1 -