Single Choice

The value of $$cos^{2}30^{0}-cos^{2}60^{0}-cos 60^{0}$$ is

A$$0$$
Correct Answer
B$$\dfrac{1}{2}$$
C$$\dfrac{3}{4}$$
D$$1$$

Solution

$$cos^{2}30^{0}-cos^{2}60^{0}-cos 60^{0}={ \left( \frac { \sqrt { 3 } }{ 2 } \right) }^{ 2 }-{ \left( \frac { 1 }{ 2 } \right) }^{ 2 }-\frac { 1 }{ 2 } =\frac { 3 }{ 4 } -\frac { 1 }{ 4 } -\frac { 1 }{ 2 } =\frac { 3-1-2 }{ 4 } =0$$

SIMILAR QUESTIONS

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