Math Problem Statement

If tan⁡〖θ+1/tan⁡θ =2〗 then the value of cosec θ is
1                     (b) 1/√2                     (c) √2                     (d) √3/2

Solution

To solve for cscθ\csc \theta given the equation tanθ+1tanθ=2\tan \theta + \frac{1}{\tan \theta} = 2, we can proceed as follows:

Step 1: Let tanθ=x\tan \theta = x

Given that: tanθ+1tanθ=2\tan \theta + \frac{1}{\tan \theta} = 2 Substitute tanθ=x\tan \theta = x: x+1x=2x + \frac{1}{x} = 2

Step 2: Solve the equation

Multiply both sides by xx: x2+1=2xx^2 + 1 = 2x Rearranging terms gives: x22x+1=0x^2 - 2x + 1 = 0 (x1)2=0(x - 1)^2 = 0 So, x=1x = 1.

Step 3: Find sinθ\sin \theta and cosθ\cos \theta

Since tanθ=1\tan \theta = 1, we know that: sinθ=cosθ\sin \theta = \cos \theta

Step 4: Find sinθ\sin \theta

We use the identity: tanθ=sinθcosθ=1    sinθ=cosθ\tan \theta = \frac{\sin \theta}{\cos \theta} = 1 \implies \sin \theta = \cos \theta

Since sin2θ+cos2θ=1\sin^2 \theta + \cos^2 \theta = 1: sin2θ+sin2θ=1\sin^2 \theta + \sin^2 \theta = 1 2sin2θ=12 \sin^2 \theta = 1 sin2θ=12\sin^2 \theta = \frac{1}{2} sinθ=12\sin \theta = \frac{1}{\sqrt{2}}

Step 5: Find cscθ\csc \theta

The cosecant is the reciprocal of the sine: cscθ=1sinθ=2\csc \theta = \frac{1}{\sin \theta} = \sqrt{2}

Final Answer:

cscθ=2\csc \theta = \sqrt{2}

So, the correct option is (c) 2\sqrt{2}.


Would you like a more detailed explanation or have any questions? Here are some related questions you might find interesting:

  1. What is the relationship between tanθ\tan \theta and cscθ\csc \theta?
  2. How to solve equations involving trigonometric identities?
  3. What is the value of sinθ\sin \theta and cosθ\cos \theta for θ=45\theta = 45^\circ?
  4. How to derive the identity sin2θ+cos2θ=1\sin^2 \theta + \cos^2 \theta = 1?
  5. What is the reciprocal of cosθ\cos \theta in trigonometry?

Tip: In trigonometry, knowing a few fundamental identities can simplify complex expressions and make it easier to solve equations.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Trigonometry
Algebra

Formulas

tan θ + 1/tan θ = 2
cosec θ = 1/sin θ
sin^2 θ + cos^2 θ = 1

Theorems

Trigonometric identities
Pythagorean identity

Suitable Grade Level

Grades 10-12