Solve sin245^circsin125^circ+sin155^circsin35^circ

$$\sin 245 ^ { \circ } \sin 125 ^ { \circ } + \sin 155 ^ { \circ } \sin 35 ^ { \circ }$$

Evaluate

$$-0.4999999999999999789902746734254$$

Solution Steps

Evaluate trigonometric functions in the problem

$$-0.9063077870366497 \cdot 0.819152044288992 + 0.4226182617406995 \cdot 0.573576436351046$$

Multiply -0.9063077870366497 and 0.819152044288992 to get -0.7424038765061040046582822701024.

$$-0.7424038765061040046582822701024+0.4226182617406995\times 0.573576436351046$$

Multiply 0.4226182617406995 and 0.573576436351046 to get 0.242403876506104025668007596677.

$$-0.7424038765061040046582822701024+0.242403876506104025668007596677$$

Add -0.7424038765061040046582822701024 and 0.242403876506104025668007596677 to get -0.4999999999999999789902746734254.

$$-0.4999999999999999789902746734254$$