Question

the value of 4 sin^2 60+3tan^2 30-8sin^2 45 - cos^2 45.

Answer 1

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Answer 2

$= 4 sin^2 60+3tan^2 30-8sin^2 45 - cos^2 45 \\ \\ = 4 \times { (\frac{ \sqrt{3} }{2}) }^{2} + 3 \times {( \frac{1}{ \sqrt{3} } )}^{2} - 8 \times {( \frac{1}{ \sqrt{2} } )}^{2} - {( \frac{1}{ \sqrt{2} } )}^{2} \\ \\ = (4 \times \frac{3}{4} ) +( 3 \times \frac{1}{3}) - (8 \times \frac{1}{2} ) - (\frac{1}{2} ) \\ \\ = 3 + 1 - 4 - \frac{1}{2} \\ \\ = - \frac{1}{2}$