Sin inverse 1 by root 5 + Cos inverse X is equal to 1. find x?

1 Answer
Oct 18, 2017

#x~~0.8595783384#

Explanation:

Given
#color(white)("XXX")arcsin(1/sqrt(5))+arccos(x)=1#

#color(white)("XXX")rarr arccos(x)=1-arcsin(1/sqrt(5))#

Note: I have assumed angles are in Quadrant I

Using a calculator (or spreadsheet function)
#color(white)("XXX")arcsin(1/sqrt(5))~~0.463647609#

Therefore
#color(white)("XXX")arccos(x)~~1-0.463647609 =0.53352391#
and
#color(white)("XXX")cos(arccos(x))~~cos(0.53352391)#

#color(white)("XXX")rarr x~~cos(0.53352391)#

Then using a calculator or spreadsheet function again
#color(white)("XXX")x~~0.8595783384#