Question

o valor de sen1200 é igaul a:​

Answer 1

$\sf sin \left(1200^{\circ \:}\right)\\\\\\\sf sin \left(x\right)=cos \left(90^{\circ \:}-x\right)\\\\\\\sf sin \left(1200^{\circ \:}\right)=cos \left(90^{\circ \:}-1200^{\circ \:}\right)\\\\\\\sf cos \left(90^{\circ \:}-1200^{\circ \:}\right)\\\\\\\sf cos \left(-1110^{\circ \:}\right)\\\\\\\sf \left(-1110^{\circ \:}\right)=cos \left(1110^{\circ \:}\right)\\\\\\\sf cos \left(30^{\circ \:}\right)\\\\\\\boxed{\sf \frac{\sqrt{3}}{2}}$