Solve the simultaneous equations y = √x+2 and (y+x)(y−x)=0 ?
1 Answer
Nov 18, 2017
Explanation:
y=√x+2→(1)
(y+x)(y−x)=0←factors of difference of squares
⇒y2−x2=0→(2)
substitute y=√x+2 into equation (2)
(√x+2)2−x2=0
multiply through by −1
x2−x−2=0←in standard form
the factors of - 2 which sum to - 1 are +1 and - 2
⇒(x+1)(x−2)=0
equate each factor to zero and solve for x
x+1=0⇒x=−1
x−2=0⇒x=2
substitute these values into equation (1)
x=−1→y=√−1+2=1
x=2→y=√2+2=2
points of intersection are (−1,1) and (2,2)