Question 1132131
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<pre>
(a)  (tan69° + tan66°)/(1 - tan69°tan66°) = 


             apply the formula  tan(a+b) = {{{(tan(a) + tan(b))/(1-tan(a)*tan(b))}}}


     = tan(69° + 66°) = tan(135°) = tan(180° + 45°) = 1.     <U>ANSWER</U>




(b)  (sin45°cos15° + sin15°cos45°)/(sin45°cos15° - sin15°cos45°) = 


             apply the formula  sin(a+b) = sin(a)*cos(b) + cos(a)*sin(b)  to the numerator;

             apply the formula  sin(a-b) = sin(a)*cos(b) - cos(a)*sin(b)  to the denominator.


      = {{{sin(45^o+15^o)/sin(45^o-15^o)}}} = {{{sin(60^o)/sin(30^o)}}} = {{{((sqrt(3)/2))/((1/2))}}} = {{{sqrt(3)}}}.     <U>ANSWER</U>
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Solved.