2007-12-15 20:11:45 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
f (x) = - 3 sin 3x + 7 cos 7x
f `(x) = - 9 cos 3x - 49 sin 7x
2007-12-15 20:50:34 · answer #1 · answered by Como 7 · 3⤊ 2⤋
f(x) = -3sin 3x + 7cos7x
f'(x) = (-3sin3x)' + (7cox7x)'
(-3xsin3x)' = (-3)' * (sin3x) + (-3) * (sin3x)'
= 0 * sin3x - 3 * cos(3x) * 3
= 0 - 9 * cos3x
= -9cos3x
(7cos7x)' = (7)' * (cos7x) + (7) * (cos7x)'
= 0 * cos7x + 7 * (-sin(7x) * 7)
= 0 - 49 sin7x
(-3xsin3x)' + (7cos7x)' = -9cos3x - 49sin7x
Final answer
-(9cos3x + 49sin7x)
2007-12-16 05:16:33 · answer #2 · answered by Rayan Ghazi Ahmed 4 · 0⤊ 2⤋
f'(x) = (-3cos3x)3 +(-7sin7x)7 = - 9cos3x - 49sin7x
2007-12-16 04:22:02 · answer #3 · answered by piano 7 · 1⤊ 1⤋
-9cos3x-49sin7x
2007-12-16 04:16:19 · answer #4 · answered by Tarun S 2 · 1⤊ 1⤋
f'=-9cos3x-49sin7x
2007-12-16 04:57:02 · answer #5 · answered by someone else 7 · 1⤊ 3⤋