x

Using sec(x), cosec(x), and cot(x)

\(\DeclareMathOperator{cosec}{cosec}\)

Show that \(\frac{\cot x \sec x}{\cosec^2 x}=\sin x\)
  • \[\text{LHS}= \frac{\cot x \sec x}{\cosec^2 x}=\frac{\frac{\cos x}{\sin x}\frac{1}{\cos x}}{\frac{1}{\sin^2x}}\]
  • \[= \frac{\frac{1}{\sin x}}{\frac{1}{\sin^2 x}}\]
  • \[=\frac{1}{\sin x}\times \frac{\sin^2x}{1}\]
  • \[=\frac{\sin^2x}{\sin x}\]
  • \[=\sin x\]
  • \[=\text{RHS}\]
Solve \(\sec x = \sqrt{ 2 }\) in the interval \(0\leq x\leq2\pi\)
  • \[\cos x=\frac{1}{\sqrt{ 2 }}\]
  • \[x=\frac{\pi}{4}\]
  • \(\(x=\frac{7\pi}{4}\)\)
    Using cast circle ^
Left-click: follow link, Right-click: select node, Scroll: zoom
x