Question

Please please help it’s my last question! :) thankyou

Answer 1

(-2.65, 3) and (0, -4) and (2.65, 3)

Explanation:

`\left\{\begin{array}{ccc}x^2+y^2=16&(1)\\y+4=x^2&(2)\end{array}\right\qquad\text{substitute (2) to (1)}\\\\(y+4)+y^2=16\\y^2+y+4=16\qquad\text{subtract 16 from both sides}\\y^2+y-12=0\\y^2+4y-3y-12=0\\y(y+4)-3(y+4)=0\\(y+4)(y-3)=0\iff y+4=0\ \vee\ y-3=0\\\\y+4=0\qquad\text{subtract 4 from both sides}\\\boxed{y=-4}\\\\y-3=0\qquad\text{add 3 to both sides}\\\boxed{y=3}`

`\text{Put the values of y to (2)}:\\\\\text{for}\ y=-4\\x^2=-4+4\\x^2=0\to x=\sqrt0\to\boxed{x=0}\\\\\text{for}\ y=3\\x^2=3+4\\x^2=7\to x=\pm√(7)\\\boxed{x=-\sqrt7\approx-2.65}\ \vee\ \boxed{x=\sqrt7\approx2.65}`