Nilaikan
-\frac{\sqrt{2}}{2}\approx -0.707106781
Kongsi
Disalin ke papan klip
\cos(\pi +\frac{\pi }{4})=\cos(\pi )\cos(\frac{\pi }{4})-\sin(\frac{\pi }{4})\sin(\pi )
Gunakan \cos(x+y)=\cos(x)\cos(y)-\sin(y)\sin(x) dimana x=\pi dan y=\frac{\pi }{4} untuk mendapatkan hasil.
-\cos(\frac{\pi }{4})-\sin(\frac{\pi }{4})\sin(\pi )
Dapatkan nilai \cos(\pi ) daripada nilai trigonometric.
-\frac{\sqrt{2}}{2}-\sin(\frac{\pi }{4})\sin(\pi )
Dapatkan nilai \cos(\frac{\pi }{4}) daripada nilai trigonometric.
-\frac{\sqrt{2}}{2}-\frac{\sqrt{2}}{2}\sin(\pi )
Dapatkan nilai \sin(\frac{\pi }{4}) daripada nilai trigonometric.
-\frac{\sqrt{2}}{2}-\frac{\sqrt{2}}{2}\times 0
Dapatkan nilai \sin(\pi ) daripada nilai trigonometric.
-\frac{\sqrt{2}}{2}
Lakukan pengiraan.
Contoh
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Trigonometri
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Persamaan linear
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Aritmetik
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Matriks
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Persamaan serentak
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Pembezaan
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Pengamiran
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Had
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