Use the local linear approximation to approximate a value for f (x)= sec 121 degrees.

Answer 1

f = secx
df = secx tanx dx

dx = 1° = 0.01745 radians

df = -2(-√3) * 0.01745 = .0604
so, sec 121° = -2 + .0604 = -1.9396

actual value: -1.9416