Question 1169844
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(1) Given cos(alpha) and cos(beta) and the fact that both angles are in quadrant I, use {{{sin(x)^2+cos(x)^2=1}}} to find sin(alpha) and sin(beta).<br>
(2) {{{cos(alpha+beta) = cos(alpha)*cos(beta)-sin(alpha)*sin(beta)}}}
(3) {{{sin(alpha+beta) = sin(alpha)*cos(beta)+cos(alpha)*sin(beta)}}}<br>
You can do the calculations.