Buktikan bahwa tan75 + cot75 = 4.

tan75 ° = tan (30 ° + 45 °)

=(tan30°+tan45°)/(1-tan30°tan45°)

={(1/√3)+1}/{1-(1/√3)(1)}

=(√3+1)/(√3-1)

Jadi, cot75°=1/tan75°

=(√3-1)/(√3+1)

Kemudian,tan75°+cot75°={(√3+1)2+(√3-1)2}/{(√3)2-(1)2}

=(3+1+2√3+3+1-2√3)/(3-1)

=4.

10