Jika tan² 45 - cos ² 30 = x. Sin 45. Cos 45 maka x

[tex] \tan45 \: = 1 \\ \cos30 = \frac{1}{2} \sqrt{3} \\ \sin45 = \frac{1}{2} \sqrt{2} \\ \cos45 = \frac{1}{2} \sqrt{2} \\ = {1}^{2} - {( \frac{1}{2} \sqrt{3)} }^{2} = x . \frac{1}{2} \sqrt{2} \: .\frac{1}{2} \sqrt{2} \\ = 1 - 0.75 = x \: 0.5 \\ = 0.25 = x \: 0.5 \\ x \: 0.5 = 0.25 \\ x = \frac{0.25}{0.5} \\ x = 0.5[/tex]
Semoga bermanfaat.....
-Prisco