Question

If sinX= 0.9, what is the value of cos X?

Round the value to the nearest thousandth.

Answer 1

Answer: sqrt(19)/10

Explanation:

sinx=0.9

x=arcsin(0.9)

Insert x for cos(x):

cos(arcsin(0.9)=

Use identify
`cos(arcsin(x))=\sqrt{1-x^(2) }`, so

`\sqrt{1-((9)/(10))^(2)} =\sqrt{(19)/(100) } =(√(19))/(10)`

Sorry if this is confusing.