
CBSE Class 10 Sample Paper for 2025 Boards - Maths Standard
CBSE Class 10 Sample Paper for 2025 Boards - Maths Standard
Last updated at Dec. 13, 2024 by Teachoo
Question 23 Evaluate: (2 sin^2〖60°〗 − tan^2〖30°〗)/sec^2〖45°〗 (2 sin^2〖60°〗 − tan^2〖30°〗)/sec^2〖45°〗 = (2(√3/2)^2 −(1/√3)^2)/(1/cos^2〖45° 〗 ) = [𝟐(√𝟑/𝟐)^𝟐 −(𝟏/√𝟑)^𝟐 ] ×〖𝒄𝒐𝒔〗^𝟐〖𝟒𝟓° 〗 = [2(√3/2)^2 −(1/√3)^2 ] ×(1/√2)^2 = [𝟐 ×𝟑/𝟒 −𝟏/𝟑] ×𝟏/𝟐 = [3/2 −1/3] ×1/2 = [(3 × 3 − 1 × 2)/(2 × 3)] ×1/2 = [(9 − 2)/6] ×1/2 = 7/6 ×1/2 = 𝟕/𝟏𝟐