Get Answers to all your Questions

header-bg qa

Provide solution for RD Sharma maths class 12 chapter 28 The Plane exercise Fill in the blank question 10

Answers (1)

Answer:

 1

Hint:

 Use formulae of circumantce after finding c0-ordinates

Given:

x + αy  +2 = 5 

Solution:

Given equation of plane

x + \alpha y +2=5\Rightarrow \frac{x}{5}+\frac{\alpha y}{5}+\frac{z}{5}=1

Comparing above equation with equation of plane in intercept from

\frac{x}{x_{1}}+\frac{y}{y_{1}}+\frac{z}{z_{1}}=1

x_1=5,y_1=5,z_1=5

So coordinates of points A,B,C?A(5,0,0),B(0,5,0),C(0,0,5)

Let circumentre D(x,y,z)

\therefore AD=\sqrt{(x-5)^{2}+y^{2}+z^{2}}, BD=\sqrt{x^{2}+(y-5)^{2}+z^{2}}, CD=\sqrt{x^{2}+y^{2}+(z-5)^{2}}

AD=BD=CD ?  taking AD=BD

\Rightarrow \sqrt{(x-5)^{2}+y^{2}+z^{2}}=\sqrt{x^{2}+(y-5)^{2}+z^{2}}

On squaring both sides

(x - 5)2 + y2 + z2 = x2 + (y - 5)2 + z2 ? 1 = 1

∴  from equation (1) ,x,y  can be x=1, y=1

∴ α=1 (also)(by solving)

Posted by

Gurleen Kaur

View full answer

Crack CUET with india's "Best Teachers"

  • HD Video Lectures
  • Unlimited Mock Tests
  • Faculty Support
cuet_ads