Find sn for the given arithmetic series.
a1 = –74, d = –3, n = 20

- 1050

Step-by-step explanation:

The sum to n terms of an arithmetic sequence is

= [ 2a₁ + (n - 1)d ], thus

= [ (2 × - 74) + (19 × - 3) ]

= 10 ( - 148 - 57) = 10 × - 105 = - 1050

f(x) has value 150 at x= 0

and 0 at x= 3

so d(f(x))/dt = slope = -150/3 = -50