Question

Cosβ=-√2/10. find the angle. plz help me​

Answer 1

Answer:
`98.13\ \text{or}\ 261.87^(\circ)`

Explanation:

Given

`\cos \beta =-(√(2))/(10)`

As the value of cosine is negative, therefore the angle must lie in II or III quadrant

`\Rightarrow \beta =\cos^(-1)(-(√(2))/(10))\\\Rightarrow \beta=\cos^(-1)(-0.14142)\\\Rightarrow \beta =98.13^(\circ)\ \text{or}\ 270^(\circ)-8.13\\\Rightarrow \beta=98.13^(\circ)\ \text{or}\ 261.87^(\circ)`