2006-11-04 20:13:38 · 13 answers · asked by Anonymous in Science & Mathematics ➔ Physics
cos(180)=cos(180-120)= -sin60= -o.5
negative sign because cos is - in ii quadrant.
you are absolutely right
2006-11-04 22:59:59 · answer #1 · answered by siddu 1 · 0⤊ 0⤋
Yes because 120 deg. lies in the 2nd quadrant where cos (theta) is always negetive.
Also, cos(180-theta)=-cos (theta)
=>cos(180-60)=-cos(60)=-1/2=-.05
2006-11-07 05:03:38 · answer #2 · answered by sushant 3 · 0⤊ 0⤋
cos(120)= -1/2
2006-11-05 04:23:10 · answer #3 · answered by No matter what happens i ll... 2 · 0⤊ 0⤋
yes
cos(120)= cos(90+30)
=-sin30
=-1/2=-0.5
2006-11-05 04:33:23 · answer #4 · answered by bhuwan_bhaskar1982 1 · 1⤊ 0⤋
Yes.
2006-11-05 04:21:33 · answer #5 · answered by Jason 3 · 0⤊ 0⤋
yes
2006-11-05 04:20:01 · answer #6 · answered by ElDarado05 2 · 0⤊ 0⤋
If you mean cos(120º), that is correct.
2006-11-05 04:19:12 · answer #7 · answered by gp4rts 7 · 0⤊ 1⤋
cos(90+teta)=-sin(teta)
cos(120)=cos(90+30)=-sin(30)=-0.5
2006-11-05 06:26:10 · answer #8 · answered by farzad g 2 · 0⤊ 0⤋
yes. cos120 = -0.5
2006-11-05 05:47:48 · answer #9 · answered by sara2005_unique 1 · 0⤊ 0⤋
Correct!!!!!!!!
2006-11-06 12:06:33 · answer #10 · answered by a 1 · 0⤊ 0⤋