English

If sin A − cosec A = 2, the value of sin2 A + cosec2 A is ______.

Advertisements
Advertisements

Question

If sin A − cosec A = 2, the value of sin2 A + cosec2 A is ______.

Options

  • 2

  • 0

  • 4

  • 6

MCQ
Fill in the Blanks
Advertisements

Solution

If sin A − cosec A = 2, the value of sin2 A + cosec2 A is 6.

Explanation:

Given sin A − csc A = 2. Since \[\csc A = \frac{1}{\sin A}\], we can square both sides of the equation:

\[\left(\sin A - \frac{1}{\sin A}\right)^2 = 2^2\]

\[\sin^2 A + \frac{1}{\sin^2 A} - 2(\sin A)\left(\frac{1}{\sin A}\right) = 4\]

sin2 A + csc2 A − 2 = 4

sin2 A + csc2 A = 4 + 2

∴ sin2 A + csc2 A = 6

shaalaa.com
  Is there an error in this question or solution?
Chapter 21: Trigonometrical Ratios [Sine, Consine, Tangent of an Angle and their Reciprocals] - Exercise 21 (B) [Page 318]

APPEARS IN

Selina Concise Mathematics [English] Class 9 ICSE
Chapter 21 Trigonometrical Ratios [Sine, Consine, Tangent of an Angle and their Reciprocals]
Exercise 21 (B) | Q 1. (d) | Page 318
Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×