prove that :tan20 tan30 tan40 =tan10

how can the value of tan30 be found?

tan60=2 tan30/1-tan^2 30 sqrt(3)=I'm confused of that 2 but i guess it means to multiply. again....

If xy log(x+y) = 1, prove that dy/dx = -y(x^2y +x+ y)/x(xy^2 + x + y)

If A + B + C = 180°, Prove that Cos²A + Cos²B - Cos²C = 1 – 2sinAsinBcosC

If A + B + C = 180°, Prove that Sin² (A/2) + sin² (B/2) + sin²(C/2) = 1 – 2sin (A/2) sin (B/2) sin(...

Simplify: sin60/tan30

Prove : Tan20+4Tan20=√3

Tan20+4sin20=√3

Tan30

Prove :Tan20+4sin20=square root 3

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