-49 + Fsin 155 + fsin 70 = 0 and Fcos 155 + f cos 70 = 0, What are the values for F and f?Please explain steps

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-49 + Fsin 155 + fsin 70 = 0 and Fcos 155 + f cos 70 = 0, What are the values for F and f?Please explain steps

2007-09-27 03:24:25 · 1 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics

1 answers

Fsin155 + fsin70 = 49
Fcos155 + fcos70 = 0

multiply the 1st by cos70 and the 2nd by sin70

Fsin155cos70 + fsin70cos70 = 49cos70
Fcos155 sin70 + fcos70sin70 = 0

by difference :

F(sin155cos70 - cos155sin70) = 49cos70

F sin(155 - 70) = 49 cos70

F = 49cos70 / sin85

With the same method : f = 49cos155 / sin(-85) = -49cos155 / sin85

2007-09-27 05:39:24 · answer #1 · answered by Nestor 5 · 0⤊ 0⤋