SOLUTION: two lines, L1 and L2, intersect at (4,7) and are perpendicular to each other. the y-intercept of L1 is 9 what is the gradient of L1???

Algebra ->  Graphs -> SOLUTION: two lines, L1 and L2, intersect at (4,7) and are perpendicular to each other. the y-intercept of L1 is 9 what is the gradient of L1???       Log On


   

Question 1025811: two lines, L1 and L2, intersect at (4,7) and are perpendicular to each other. the y-intercept of L1 is 9
what is the gradient of L1???
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Find first the equation for Line_1.
Two points on Line_1 are (0,9) and (4,7).
Slope is %287-9%29%2F%284-0%29=-2%2F4=-1%2F2.
Equation for Line_1 is y=-%281%2F2%29x%2B9.

The question of finding gradient of Line_1 reads like you want the slope;
which is now found, -1%2F2, for LINE_1.

The slope of Line_2 is the negative reciprocal of that of line_1 because these
two lines were given as perpendicular, so Line_2 has slope 2.