Question

just need a little help finishing!!!!! Write the first five terms of the trigonometric series and approximate the value of cos π to four decimal places. Compare your answer to the actual value.

this is what i have so far: 1, 4.935, 4.059, 1.335, .235

Answer 1

it adds to -.976

Answer 2

but cos (pi) is .998

Answer 3

\[\cos(\pi)=-1\]
your calculator might be set to degrees mode rather than radies mode