Answer :

y = -7sin(x) + 2cos(x)
y = -7sin(3π/4) + 2cos(3π/4)
y = -7sin(9.42/4) + 2cos(9.42/4)
y = -7sin(2.355) + 2cos(2.355)
y = -7(0.03698381721) + 2(0.9993158646)
y = -0.2588867205 + 1.998631729
y = 1.739745009

Other Questions