y=-3x^2-12x+5
step 1...find zeroes...yuze quadratik equashun
zeroes=-4.380476143 & +0.380476143
-b/21=-2, b^2-4ac=204, sqrt(204)=14.282856857, sqrt/21=-2.38047614284
step 2...tu find top or bottom...dy/dx=-6x-12, slope=0 at 6x=-12, or x=-2
at x=-2, y=-3*4 -2*(-12)+5...=-12+24+5=12+5=17, so top=(-2,17)
y-intersept...x=0, so y=5 or(0,5)
x-intersept...y=0, so -3x^2-12x+5=0...thats the 2 zeroes up abuv