AP EAMCET · Maths · Straight Lines
When the coordinate axes are rotated through an angle of \(45^{\circ}\) about the origin in the positive direction, if the transformed equation of a curve is \(17 x^2-16 x y+17 y^2=225\), then the original equation of that curve is
- A \(25 x^2+9 y^2=225\)
- B \(9 x^2-25 y^2=225\)
- C \(25 x^2-16 x y+9 y^2=225\)
- D \(9 x^2+25 y^2=225\)
Answer & Solution
Correct Answer
(A) \(25 x^2+9 y^2=225\)
Step-by-step Solution
Detailed explanation
When the axes are rotated through \(45^{\circ}\) about the origin in the positive direction then replace \((x, y)\) by \(\left(\frac{x}{\sqrt{2}}+\frac{y}{\sqrt{2}}, \frac{-x}{\sqrt{2}}+\frac{y}{\sqrt{2}}\right)\) So, original equation of the curve,…
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Maths
- If the system of equations \(a_1 x+b_1 y+c_1 z=0\), \(a_2 x+b_2 y+c_2 z=0, \quad a_3 x+b_3 y+c_3 z=0\) has only trivial solution, then the rank of \(\left[\begin{array}{lll}a_1 & b_1 & c_1 \\ a_2 & b_2 & c_2 \\ a_3 & b_3 & c_3\end{array}\right]\) isAP EAMCET 2024 Easy
- The point \((1,3)\) with respect to the ellipse \(4 x^2+9 y^2-16 x-54 y+61=0\) liesAP EAMCET 2021 Easy
- \(\int \frac{13 \cos 2 x-9 \sin 2 x}{3 \cos 2 x-4 \sin 2 x} d x=\)AP EAMCET 2025 Medium
- From a point \(P(0, b)\) two tangents are drawn to the circle \(x^2+y^2=16\) and these two tangents intersect \(X\)-axis is two points \(A\) and \(B\). If the area of \(\triangle P A B\) is minimum, then the equation of its circumcircle isAP EAMCET 2018 Medium
- The square of the distance from the origin to the point of intersection of the pair of lines \(a x^2+2 h x y-a y^2+2 g x+\) \(2 \mathrm{fy}+\mathrm{c}=0\) isAP EAMCET 2023 Medium
- If \(\tan \mathrm{B}=\frac{2 \sin \mathrm{A} \sin \mathrm{C}}{\sin (\mathrm{A}+\mathrm{C})}\), then \(\tan \mathrm{A}, \tan \mathrm{B}\) and \(\tan \mathrm{C}\) are inAP EAMCET 2023 Medium
More PYQs from AP EAMCET
- At any point on a curve if the length of the subnormal is and the curve passes through then the curve is a conic. A vertex of the curve isAP EAMCET 2022 Hard
- Match the following

The correct answer isAP EAMCET 2018 Medium - Suppose a circle passes through \((0, a)\) and \((b, h)\) having its centre at \((c, 0)\). Then the value of \(c\) isAP EAMCET 2022 Medium
- In the Dewar's method of separation of noble gases, the mixture of noble gases is kept in contact with coconut charcoal at \(173 \mathrm{~K}\) which one of the following gaseous mixtures is not adsorbed on to the charcoal?AP EAMCET 2004 Medium
- If a circle \(S\) with radius 5 touches the circle \(x^2+y^2-6 x-4 y-12=0\) at \((-1,-1)\), then the length of the tangent from the centre of the circle \(S\) to the given circle isAP EAMCET 2018 Medium
- The flow rate of water from a tap of diameter \(1.25 \mathrm{~cm}\) is 3 litres per min. If coefficient of viscosity of water is \(10^{-3} \mathrm{~Pa}-\mathrm{s}\). the nature of flow isAP EAMCET 2021 Medium