You can put this solution on YOUR website! I assume that the instructions for the problem say to find the exact value.

2015年6月15日 · tan(195^o) = tan(390^o/2) The identity you need is: tan(x/2) = pmsqrt((1-cosx)/(1+cosx)) + if quadrant I or III - if quadrant II or IV It's derived from: sin(x/2) = pmsqrt((1-cosx)/2) + if quadrant I or II - if quadrant III or IV cos(x/2) = pmsqrt((1+cosx)/2) + if quadrant I or IV - if quadrant II or III Divide the quadrant conditions …

How do you use the angle sum or difference identity to find the exact value of #tan195#? Trigonometry Trigonometric Identities and Equations Sum and Difference Identities 1 Answer

2015年9月19日 · Fin tan (-195) Ans: sqrt3 - 2 Call tan (-195) = t tan (- 390) = 2t = tan (-30 - 360) = tan (-30) = - tan (30) = - 1/sqrt3 Apply trig identity: tan 2t = (2t)/(1 - t^2 ...

2016年3月24日 · tan (-195) = - tan (195). Evaluate tan (195). Apply the trig identity: #tan 2a = (2tan a)/(1 - tan^2 a)# tan ((2(195)) = tan 390 = tan (30 + 360) = tan 30 = 1/sqrt3

Here is an example of using a sum identity: Find #sin15^@#.. If we can find (think of) two angles #A# and #B# whose sum or whose difference is 15, and whose sine and cosine we know.

Without using calculator or table of multiplication, show that #tan 195° = (sqrt3-1)/(sqrt3+1)#.?

Questions and Videos on Sum and Difference Identities, within Trigonometry