If cosx= -1/2 for 90degrees

If cosx= -1/2 for 90degrees<x<180degrees,calculate cosx/sinx
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2. asked by soml
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how to calculate If cosx= -1/2 for 90degrees<x<180degrees,calculate cosx/sinx
1. 1 answer
2. asked by soml
3. 100 views
Simplify #3:[cosx-sin(90-x)sinx]/[cosx-cos(180-x)tanx] = [cosx-(sin90cosx-cos90sinx)sinx]/[cosx-(cos180cosx+sinx180sinx)tanx] =
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2. asked by Anonymous
3. 1,054 views
hey, i would really appreciate some help solving for x when:sin2x=cosx Use the identity sin 2A = 2sinAcosA so: sin 2x = cos x
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2. asked by elle
3. 693 views
I have a question relating to limits that I solvedlim(x-->0) (1-cosx)/2x^2 I multiplied the numerator and denominator by
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2. asked by Alex
3. 674 views
Trigonometric IdentitiesProve: (tanx + secx -1)/(tanx - secx + 1)= tanx + secx My work so far: (sinx/cosx + 1/cosx +
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2. asked by Dave
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sin2x+cosx=0 , [-180,180)= 2sinxcosx+cosx=0 = cosx(2sinx+1)=0 cosx=0 x1=cos^-1(0) x1=90 x2=360-90 x2=270 270 doesn't fit in
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2. asked by Anonymous
3. 895 views
Solve this equation fo rx in the interval 0<=x<=3603sinxtanx=8 I would do it this way: sinxtanx = 8/3 sinx(sinx/cosx)=8/3
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2. asked by Edward
3. 961 views
I can't seem to prove these trig identities and would really appreciate help:1. cosx + 1/sin^3x = cscx/1 - cosx I changed the 1:
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2. asked by Heather
3. 1,250 views
i am trying to solve for A and B....this question comes from a Differential equations...but this step goes back to basics...Asin
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2. asked by mary
3. 579 views