Question

giải phương trình a) tan(2x - 30 độ) + căn 3 = 0 b) cot2x-1 = 0 c) cot3x + căn 3 = 0

Answer 1

a: \(PT\Leftrightarrow tan\left(2x-30^0\right)=-\sqrt{3}\)

=>\(2x-30^0=-60^0+k\cdot180^0\)

=>\(2x=-30^0+k\cdot180^0\)

=>\(x=-15^0+k\cdot90^0\)

b: \(cot2x-1=0\)

=>cot2x=1

=>\(2x=\dfrac{\Omega}{4}+k\cdot\Omega\)

=>\(x=\dfrac{\Omega}{8}+\dfrac{k\Omega}{2}\)

c: \(cot3x+\sqrt{3}=0\)

=>\(cot3x=-\sqrt{3}\)

=>\(3x=-\dfrac{\Omega}{6}+k\Omega\)

=>\(x=-\dfrac{\Omega}{18}+\dfrac{k\Omega}{3}\)