If 2 sin 2 ⁡β – cos 2 ⁡β  = 2, then β is

(a) 0ᵒ   (b) 90ᵒ   (c) 45ᵒ   (d) 30ᵒ

Ques 7 (MCQ) - If 2sin^2 β – cos^2 β = 2, then β is - Teachoo SQP - CBSE Class 10 Sample Paper for 2022 Boards - Maths Standard [MCQ]

part 2 - Question 7 - CBSE Class 10 Sample Paper for 2022 Boards - Maths Standard [MCQ] - Solutions of Sample Papers for Class 10 Boards - Class 10

Share on WhatsApp

Transcript

Question 7 If 2 sin^2⁡𝛽 – cos^2⁡𝛽 = 2, then β is (a) 0ᵒ (b) 90ᵒ (c) 45ᵒ (d) 30ᵒ Given 2 sin^2⁡𝛽 – cos^2⁡𝛽 = 2 – cos^2⁡𝛽 = 2 − 2 sin^2⁡𝛽 – 〖𝒄𝒐𝒔〗^𝟐⁡𝜷 = 2(1 − 〖𝒔𝒊𝒏〗^𝟐⁡𝜷) – cos^2⁡𝛽 = 2 cos^2⁡𝛽 0 = 2 cos^2⁡𝛽 "+ " cos^2⁡𝛽 0 = 3 cos^2⁡𝛽 3 cos^2⁡𝛽 = 0 cos^2⁡𝛽 = 0 𝒄𝒐𝒔⁡𝜷 = 0 This is possible if 𝛽 = 90° So, the correct answer is (b)

Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo