Đáp án:
Giải thích các bước giải:
`C=\frac{1}{sin\ 10^{0}}+\frac{\sqrt{3}}{cos\ 10^{0}}`
`C=\frac{cos\ 10^{0}+\sqrt{3}sin\ 10^{0}}{sin\ 10^{0}.cos\ 10^{0}}`
\(C=\dfrac{\dfrac{1}{2}cos\ 10^{0}+\dfrac{3}{2}sin\ 10^{0}}{\dfrac{1}{2}sin\ 10^{0}.cos\ 10^{0}}\)
\(C=\dfrac{sin\ 30^{0}.cos\ 10^{0}+cos\ 30^{0}.sin\ 10^{0}}{\dfrac{1}{4}.2sin\ 10^{0}.cos\ 10^{0}}\)
\(C=\dfrac{sin\ (30^{0}+10^{0})}{\dfrac{1}{4}.sin\ 20^{0}}\)
`C=4.\frac{sin\ 40^{0}}{sin\ 20^{0}}`
`C=4.\frac{2sin\ 20^{0}.cos\ 20^{0}}{sin\ 20^{0}}`
`C=8cos\ 20^{0}`
