Question

If the axes are rotated
through an angle 'e' then
the coordinates of a
point
P(x, y)
are
transformed as
P(x', y')
then P(x, y) =​

Answer 1

Answer:

6.

3(xcosθ−ysinθ)

2

−6(xcosθ−ysinθ)

(xsinθ+ycosθ)+3(xsinθ+ycosθ)

2

+7(xcosθ−ysinθ)−3=0

Coefficient of xy=0

⟹−6sinθcosθ−6(cos

2

θ−sin

2

θ)+6sinθcosθ=0

thereforecos2θ=0 ∴=

2

π

,

2

3π

∴θ=

4

π

,

4

3π

Since θ is obtuse we choose θ=

4

3π

∴ Coefficient of x

2

=3(cos

2

θ+sin

2

θ)−6sinθcosθ

=3.1−3.sin2theta=3+3=6 ∵sin2θ=sin

2

3π

=−1

hope it helps you..!!