Qus : 3 NIMCET PYQ 2022 3 If ( x a ) 2 + ( y b ) 2 = 1 , ( a > b ) and x 2 − y 2 = c 2 cut at right angles, then
1 a 2 + b 2 = 2 c 2 2 b 2 − a 2 = 2 c 2 3 a 2 − b 2 = 2 c 2 4 a 2 − b 2 = c 2 Go to Discussion NIMCET Previous Year PYQ NIMCET NIMCET 2022 PYQ Solution If
x 2 a 2 + y 2 b 2 = 1 and
x 2 c 2 + y 2 d 2 = 1 are orthogonal.
Then
a 2 − b 2 = c 2 − d 2
Similarly
If x 2 a 2 + y 2 b 2 = 1 and x 2 − y 2 = c 2 are orthogonal.
It means
x 2 a 2 + y 2 b 2 = 1 and x 2 c 2 + y 2 − c 2 = 1 are orthogonal
Then
a 2 − b 2 = c 2 − ( − c 2 )
a 2 − b 2 = 2 c 2
Qus : 4 NIMCET PYQ 2024 1 If the line a 2 x + a y + 1 = 0 , for some real number a , is normal to the curve x y = 1
then
1 a < 0 2 0 < a < 1 3 a > 0 4 − 1 < a < 1 Go to Discussion NIMCET Previous Year PYQ NIMCET NIMCET 2024 PYQ Solution
Problem:
The line a 2 x + a y + 1 = 0 is normal to the curve x y = 1 . Find possible values of a ∈ R .
Step 1: Slope of Line
Rewrite: y = − a x − 1 a → slope = − a
Step 2: Curve Derivative
x y = 1 ⇒ d y d x = − y x
Slope of normal = x y
Match Slopes
− a = x y ⇒ x = − a y
Plug into Curve
x y = 1 ⇒ ( − a y ) ( y ) = 1 ⇒ y 2 = − 1 a
For real y , we need a < 0
✅ Final Answer:
a < 0
Qus : 11 NIMCET PYQ 2023 2
Find foci of the equation x 2 + 2 x – 4 y 2 + 8 y – 7 = 0
1 ( √ 5 ± 1 , 1 ) 2 ( − 1 ± √ 5 , 1 ) 3 ( − 1 , √ 5 ± 1 ) 4 ( 1 , − 1 ± √ 5 ) Go to Discussion NIMCET Previous Year PYQ NIMCET NIMCET 2023 PYQ Solution
Finding Foci of a Conic
Given Equation: x 2 + 2 x − 4 y 2 + 8 y − 7 = 0
Step 1: Complete the square
⇒ ( x + 1 ) 2 − 4 ( y − 1 ) 2 = 4
Rewriting: ( x + 1 ) 2 4 − ( y − 1 ) 2 1 = 1
This is a horizontal hyperbola with:
Center: ( − 1 , 1 )
a 2 = 4 , b 2 = 1
c = √ a 2 + b 2 = √ 5
✅ Foci:
( − 1 ± √ 5 , 1 )
[{"qus_id":"3767","year":"2018"},{"qus_id":"4293","year":"2017"},{"qus_id":"11115","year":"2022"},{"qus_id":"11141","year":"2022"},{"qus_id":"11518","year":"2023"},{"qus_id":"11637","year":"2024"},{"qus_id":"11665","year":"2024"},{"qus_id":"10215","year":"2015"},{"qus_id":"10440","year":"2014"},{"qus_id":"10465","year":"2014"},{"qus_id":"10483","year":"2014"}]