Solve (sin90^{circ}-cos270^circ)(sin180^circ-cos90^circ)+cos180^circ

$$( \sin 90 ^ { \circ } - \cos 270 ^ { \circ } ) ( \sin 180 ^ { \circ } - \cos 90 ^ { \circ } ) + \cos 180 ^ { \circ }$$

Evaluate

$$-1$$

Solution Steps

Get the value of \sin(90) from trigonometric values table.

$$\left(1-\cos(270)\right)\left(\sin(180)-\cos(90)\right)+\cos(180)$$

Get the value of \cos(270) from trigonometric values table.

$$\left(1-0\right)\left(\sin(180)-\cos(90)\right)+\cos(180)$$

Subtract 0 from 1 to get 1.

$$1\left(\sin(180)-\cos(90)\right)+\cos(180)$$

Get the value of \sin(180) from trigonometric values table.

$$1\left(0-\cos(90)\right)+\cos(180)$$

Get the value of \cos(90) from trigonometric values table.

$$1\left(0-0\right)+\cos(180)$$

Subtracting 0 from itself leaves 0.

$$1\times 0+\cos(180)$$

Multiply 1 and 0 to get 0.

$$0+\cos(180)$$

Get the value of \cos(180) from trigonometric values table.

$$0-1$$

Subtract 1 from 0 to get -1.

$$-1$$