2016年10月19日 · Change to sines and cosines then simplify. #1+tan^2x=1+(sin^2x)/cos^2x# #=(cos^2x+sin^2x)/cos^2x# but #cos^2x+sin^2x=1#

2018年6月18日 · If you want a certain quantity to equal #1# when squared, then your quantity must be either #1# or #-1#.Every other number would not equal #1# when squared.

2016年2月21日 · color(blue)(x = 26.565051) Since the given is a "Trigonometric Function of Tangent (Tan)", and x is an angle theta (Theta), tan theta=1/2 to get the value of x or theta, we …

2016年8月2日 · Think about #tan(theta)=2#. So #theta=tan^(-1)(2)#. #color(brown)("So the question is really asking: What angle gives a tangent value of 2")#

2016年10月1日 · See explanation... Starting from: cos^2(x) + sin^2(x) = 1 Divide both sides by cos^2(x) to get: cos^2(x)/cos^2(x) + sin^2(x)/cos^2(x) = 1/cos^2(x) which simplifies to: …

2018年3月25日 · Using the identities: #1+tan^2theta= sec^2theta# #1/sectheta= costheta# #tantheta= sintheta/costheta# #sin^2theta= 1-cos^2theta#

2016年10月17日 · How do you apply the fundamental identities to values of #theta# and show that they are true

2018年1月9日 · True Start with the well known pythagorean identity: sin^2x + cos^2x -= 1 This is readily derived directly from the definition of the basic trigonometric functions sin and cos and …

2016年11月27日 · the Mac-laurin expansion is. #tan^(-1)(x)=x-x^3/3+x^5/5+o(x^6)# by replacing #x=-1/2# and taking only the first three expansion's terms we get

2017年7月12日 · See the proof below We need tanx=sinx/cosx sin^2x+cos^2x=1 secx=1/cosx Therefore, LHS=tan^2x+1 =sin^2x/cos^2x+1 =(sin^2x+cos^2x)/cos^2x =1/cos^2x =sec^2x …