intercepts of f(x)=-sqrt(x)+3
On the horizontal axis, y = 0: solve -x + 3 = 0
⇥1) Let's solve in ℝ: -x + 3 = 0
⇥2) The numeric value of: -1·(-3) is:
⇥ 3
⇥Isolate the square root: x = 3. Since the right side is nonnegative, square both sides:
⇥ x = (-1·(-3))2
⇥ⓘ Two minus signs cancel out, the product of two negative numbers is positive: -1·(-3) = 3
⇥ x = 32
⇥ⓘ An integer power is a repeated product: 32 = 3·3 = 9
⇥Candidates, pending the domain check: x = 9
⇥ For the expression -x to be defined, we must have: x ≥ 0
⇥Domain constraints: x ≥ 0
The graph crosses the horizontal axis at (9, 0)
On the vertical axis, x = 0: calculate f(0)
⇥ -0 + 3
⇥ⓘ Adding 0 changes nothing: 0 + 3 = 3
⇥ 3
▶Axis intercepts:   { (9, 0), (0, 3) }