complete the square ...
y = -4(x^2 - (3/4)x .....) - 6 , (we usually don't say +-6 to adding a negative 6 )
= -4(x^2 - (3/4)x + 9/64 - 9/64) - 6 , ( take 1/2 of 3/4 to get 3/8, now square that ----> 9/64
= -4( (x - 3/8)^2 - 9/64) - 6
= -4(x-3/8)^ + 9/16 - 6
= -4(x - 3/8)^2 - 87/16
take it from there
or
the x of the vertex is -b/(2a) = -3/-8) = 3/8
then y =-4(9/64) + 3(3/8) - 6 = -87/6
(which matches my numbers above)
Identify the form of the equation (standard, vertex, intercept), tell if it opens up or down and give the axis of symmetry.
y=-4x^2+3x+-6
Walk me through this please?
1 answer
1 answer