Answer:
y = 3x + 3
Step-by-step explanation:
y = -x² + 4x + 5
→ Find the vertex
- ( x - 2 )² + 4 + 5 ∴ vertex = ( 2 , 9 )
→ Find the intersection with the x axis
- ( x - 5 ) ( x + 1 ) ∴ ( - 1 , 0 )
→ Find the gradient of the 2 point
( 0 - 9 ) ÷ ( -1 - 2 ) = 3
→ Write into y = mx + c format
y = 3x + c
→ Substitute in a coordinate pair
0 = -3 + c ∴ c = 3
→ Rewrite into y = mx + c
y = 3x + 3
