Point slope is y-y1=m(x-x1) with the given point (-1,6), 6 is our y1 and -1 is our x1 and m is our slope which is -3 so we plug in those points to the above equation y-6= -3(x-(-1)) --> y-6= -3(x+1) --> B.
Vol of sphere =4/3πr³ let the radius of cone be x. vol of cone =1/3πx²h when h=r, =1/3πrx² since they have the same volume, 4/3πr³=1/3πrx² 4πr³=πrx² x²=4r² x=2r (radius)