Thank you Reiny for the last question! :)

Question

If you or anyone else could help me with this other question, I'd really appreciate it!

Use the trigonometric subtraction formula for sine to verify the identity:
sin(pi/2-x)=cosx

Caluculation:
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Reason:
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prnt.sc/jns55q <--- copy and paste link

Answer 1

prove sin(pi/2-x)=cosx , use the sin(A-B) = sinAcosB - cosAsinB expansion
LS = sin(π/2 - x)
= sinπ/2cos(x) - cosπ/2sinx , now recall sinπ/2 = 1, cosπ/2 = 0
= cosx - 0(sinx)
= cosx
= RS , all done

Answer 2

OMLLL! Thank you! Ily. :*