Question

The equation of plane through the points (2, 2, 1) and (9, 3, 6) and perpendicular to the plane 2x + 6y + 6z – 1 = 0 is

• A. 3x + 4y + 5z = 9
• B. 3x + 4y – 5z = 9
• C. 3x + 4y – 5z – 9 = 0
• D. None of these

Answer 1

Answer: (B)

3x + 4y – 5z = 9

Answer 2

Equation of plane passing through (2, 2, 1) is

a(x – 2) + b(y – 2) + c(z – 1) = 0

also passes through (9, 3, 6)

\ 7a + b + 5c = 0 and ^ to 2x + 6y + 6z – 1 = 0

\ 7a + b + 5c = 0 and 2a + 6b + 6c = 0

\ $\frac{a}{- 24} = \frac{b}{- 32} = \frac{c}{40}$ i.e. $\frac{a}{3} = \frac{b}{4} = \frac{c}{- 5}$

\ 3x + 4y – 5z = 9