Question

Choose the equation of the line passing through the point (-1, 7) and perpendicular to y = -x - 5.

y = -4x - 11

y = -4x - 3

y = 4x + 11

y = 4x + 3

Answer 1

Are you familiar with the slope intercept form of a line?\[y=mx+c\]

Answer 2

you mean +b? yes

Answer 3

none of the above. did you write it correctly?

Answer 4

y = -4x - 11

y = -4x - 3

y = 4x + 11

y = 4x + 3

Answer 5

those are the choices

Answer 6

what about the perpendicular line. is it correctly written too?

Answer 7

its y = -1/4x - 5.

Answer 8

there we go.

Answer 9

sorry bout that

Answer 10

it is ok

Answer 11

perpendicular lines have reciprocal(fliped) slopes and have opposite signs

Answer 12

when ever we have an equation of this form, and we need the line perpendicular to it. there is property obtained from Tan(A-B) for the lines, it tells us that \[m_1\times m_2= -1\]For example if you need the line perpendicular to y = 3x+5, then \[m\times 3 = -1\]this gives us \[m = \frac{-1}{3}\]this is the slope of the line perpendicular to y = 3x+5, now if we have a point ( as we do in the question) through which this perpendicular line passes then we plug it into\[ y = \frac{-1}{3}\times x+ C\]and solve for C.
This will give you the equation of the perpendicular line upon substitution and simplification.