The height of a sunflower being grown for a botany experiment can be modeled with a linear equation with variables y (height in cm) and x (days after measurements started). The line has a slope of 2.9. Two weeks after measurements started, the height was 49.1 cm. Use the point-slope form of a line to find the equation. How tall was the sunflower at the first measurement?

Question

m = 2.9 point is (14, 49.1)
y - 49.1 = 2.9(x - 14)
y - 49.1 = 2.9x - 40.6
y = 2.9x + 8.5

So I get it to this point of the equation. What I do not understand is the main question of "how tall was the sunflower at the first measurement"?

Would the first measurement be on day one, so, y = 2.9(1) + 8.5 = 11.4 cm, or y = 2.9(0) + 8.5 = 8.5 cm.

Thank you.

Answer 1

The problem said x (days after measurements started)
so, when x=1, that is 1 day after the 1st measurement.
At the first measurement, y=8.5

Answer 2

If x = 1 wouldn't it then be y = 2.9(1) + 8.5, so it would be 11.4, not 8.5 on the first measurement????

Answer 3

NOTE: x (days AFTER measurements started)
SO first measurement x = ZERO