Question

Answer q26 question

Answer 1

x = 2cosθ - sinθ   x² = 4cos²θ + sin²θ - 4 cosθ sinθ
y = cosθ - 3sinθ  y² = cos²θ + 9sin²θ - 6sinθcosθ
xy = (2cosθ - sinθ )(cosθ - 3sinθ) = 2cos²θ -7sinθcosθ + 3sin²θ
2x² + y² -2xy
= 8cos²θ + 2sin²θ -8sinθcosθ +cos²θ + 9sin²θ - 6sinθcosθ - 4cos²θ +14sinθcosθ - 6sin²θ = 5cos²θ + 5 sin²θ = 5

Hence proved.

Answer 2

x = 2cosθ - sinθ   x² = 4cos²θ + sin²θ - 4 cosθ sinθ

y = cosθ - 3sinθ  y² = cos²θ + 9sin²θ - 6sinθcosθ

xy = (2cosθ - sinθ )(cosθ - 3sinθ) = 2cos²θ -7sinθcosθ + 3sin²θ

2x² + y² -2xy

= 8cos²θ + 2sin²θ -8sinθcosθ +cos²θ + 9sin²θ - 6sinθcosθ - 4cos²θ +14sinθcosθ - 6sin²θ = 5cos²θ + 5 sin²θ = 5

Proved !!

please mark me as brainliest ☺️☺️