Writiing equations with perpendicular lines
I don't understand how to write an equation with a perpendicular line. The book does not have an example.
Write and equation of aline through (4, 5) that is perpendicular to y=1/2x & 3.
I have been doing equations when there are two sets of ordered pairs. This only has 1.
Please help.
Thanks
Writiing equations with perpendicular lines
Two lines are perpendicular if the product of their gradients is -1
Ie. M_1 * m_2 = -1
Where m_1 = gradient of first line
M_2 = gradient of 2nd line
The line you have is of gradient 1/2, so a line perpendicular to that would have gradient -2
Then it goes through (4,5) you said,
So using the equation
Y-5 =(-2) (x-4)
You get the answer
Writiing equations with perpendicular lines
Well to get a perpendicular slope, do the inverse recipricle of the regular slope, in this case 1/2 inverse: -1/2 and then the reciprical -2. Once you have the slope rewrite the equation in the y=mx + b form. Y=-2x + 3, and the other order pair is (0,3) and this is because the y-intercept is 3. X:4-0=4 and y:5-3=2, so the equations should be set up: y-2=-2(x+4)+3, or y-2=(-2x-8)=3.
