Question

Solve log (x + 1) = –x2 + 10 by graphing.

Which equations should be graphed?

y1 = –x2

y1 = –x2 + 10

mr001-1.jpg

y2 = log (x + 1)

Answer 1

Graph the two functions whose intersection satisfies the equation:
y1 = −x^2 + 10
y2 = log(x + 1)

Reason: any x where y1 = y2 gives log(x+1) = −x^2 + 10. (Remember the domain x > −1.)
If you want the numeric intersection (assuming log = log10), x ≈ 3.06.