Question

Sin (pi+t)+sin (2pi-t)-cos (3pi/2+t)+1.5

Answer 1

$\sin\left(\pi+t\right)+\sin\left(2\pi-t\right)-\cos\left(\frac{3\pi}2+t\right)=1,5\\-\sin t-\sin t-\sin t=1,5\\-3\sin t=1,5\\\sin t=-0,5\\t=(-1)^n\cdot\frac{7\pi}6+\pi n,\;n\in\mathbb{Z}$