Q85.Let P1 be a parabola with vertex (3, 2) and focus (4, 4) and P2 be its mirror image with respect to the line x + 2y = 6. Then the directrix of P2 is x + 2y = _____.
What This Question Tests
This question requires calculating the directrix of the initial parabola given its vertex and focus, and then finding the equation of the mirror image of this directrix with respect to a given line.
Concepts Tested
Formulas Used
Midpoint formula
Slope of perpendicular lines (m1*m2 = -1)
Equation of a line
Formula for image of a point with respect to a line
📚 NCERT Sections This Tests
9.1 — A Small Candle, 2.5 Cm In Size Is Placed At 27 Cm In Front Of A Concave
Physics Class 12 · Chapter 9
9.1 A small candle, 2.5 cm in size is placed at 27 cm in front of a concave mirror of radius of curvature 36 cm. At what distance from the mirror should a screen be placed in order to obtain a sharp image? Describe the nature and size of the image. If the candle is moved closer to the mirror, how would the screen have to be moved?
9.15 — Apply Mirror Equation And The Condition:
Physics Class 12 · Chapter 9
9.15 Apply mirror equation and the condition: (a) f < 0 (concave mirror); u < 0 (object on left) (b) f > 0; u < 0 (c) f > 0 (convex mirror) and u < 0 (d) f < 0 (concave mirror); f < u < 0 to deduce the desired result.
9.8 — A Beam Of Light Converges At A Point P. Now A Lens Is Placed In The
Physics Class 12 · Chapter 9
9.8 A beam of light converges at a point P. Now a lens is placed in the path of the convergent beam 12cm from P. At what point does the beam converge if the lens is (a) a convex lens of focal length 20cm, and (b) a concave lens of focal length 16cm?
📋 Question Details
- Chapter
- Parabola
- Topic
- Directrix of parabola, mirror image of a line
- Year
- 2022
- Shift
- 24 Jun Shift 2
- Q Number
- Q85
- Type
- Numerical
- NCERT Ref
- Class 11 Mathematics Ch 11: Conic Sections, Class 11 Mathematics Ch 10: Straight Lines
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