Answer:
y = 3
+ 4
Explanation:
Create 2 equations using values from the table to find a and b.
Using (0, 10), then
10 = acos0° + b ( cos0° = 1 ), thus
a + b = 10 → (1)
Using (90, 4), then
4 = acos90° + b ( cos90° = 0 ), thus
b = 4
Substitute b = 4 into (1)
a + 4 = 10 ( subtract 4 from both sides )
a = 6
Thus
y = 6cosx° + 4
When x = 45°, then
y = 6cos45° + 4 = 6 ×
+ 4 = 3
+ 4