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If theta is an acute angle and tan^(...

If `theta` is an acute angle and `tan^(2)theta+(1)/(tan^(2)theta)=2` , then the value of `theta` is :

A

`60^(@)`

B

`45^(@)`

C

`15^(@)`

D

`30^(@)`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the equation \( \tan^2 \theta + \frac{1}{\tan^2 \theta} = 2 \), we will follow these steps: ### Step 1: Set up the equation We start with the given equation: \[ \tan^2 \theta + \frac{1}{\tan^2 \theta} = 2 \] ### Step 2: Let \( x = \tan^2 \theta \) We can substitute \( x \) for \( \tan^2 \theta \): \[ x + \frac{1}{x} = 2 \] ### Step 3: Multiply through by \( x \) To eliminate the fraction, multiply both sides by \( x \) (assuming \( x \neq 0 \)): \[ x^2 + 1 = 2x \] ### Step 4: Rearrange the equation Rearranging gives us a standard quadratic equation: \[ x^2 - 2x + 1 = 0 \] ### Step 5: Factor the quadratic This can be factored as: \[ (x - 1)^2 = 0 \] ### Step 6: Solve for \( x \) Setting the factor equal to zero gives: \[ x - 1 = 0 \implies x = 1 \] ### Step 7: Substitute back for \( \tan^2 \theta \) Since \( x = \tan^2 \theta \), we have: \[ \tan^2 \theta = 1 \] ### Step 8: Solve for \( \theta \) Taking the square root of both sides, we find: \[ \tan \theta = 1 \] Since \( \theta \) is an acute angle, we take the positive root: \[ \theta = 45^\circ \] ### Final Answer Thus, the value of \( \theta \) is: \[ \theta = 45^\circ \]
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