Binoy kumar mahato

Popular questions and responses by Binoy kumar mahato
  1. math

    ifcosX+cosY=a and sinX+sinY=b than prove thatsin2X+sin2Y=2ab(1-2/(a^2+b^2)

    asked on October 4, 2017
  2. math

    if cos(B-C)+cos(C-A)+cos(A-B)=-3/2 then prove that cosA+cosB+cosC=O and sinA+sinB+sinC=O after that prove that cos(B-C)=cos(C-A)=cos(A-B)=-1/2

    asked on October 6, 2017
  3. math (trigonometry)

    if tan A/2 =cosecA-sin A then prove cos^2 A/2=cos 36 degree

    asked on October 24, 2017
  4. math (trigonometry)

    A=170 degree then prove that Tan A/2=-1-rot(1+Tan^2 A)/Tan A

    asked on October 23, 2017
  5. math

    limit x tends to infinity ( 1+root n)/(1-rootn)

    asked on December 3, 2017
  6. math

    cos(A-B)+cos(B-C)+cos(C-A)=-3/2 then prove that cos A+cos B+cos C=0 and sin A+sin B+sin C=0 and also prove that cos(A-B)=cos(B-C)=cos(C-A)=-1/2

    asked on October 7, 2017
  1. maths (trigonometry)

    L.H.S= cos 70/sin 70+4 cos 70 = cos 70+4 cos 70 sin 70/sin 70 =cos 70+2 sin 40/sin 70 = cos 70+2 cos 50/sin 70 = cos 70+cos 50+cos 50/sin 70 = 2 cos 60 cos 10+cos 50/sin 70 = cos 10+cos 50/sin 70 = 2 cos 30 cos 20 /cos 20 = root 3

    posted on October 8, 2017