document.write( "Question 66301: (a) Express 8 Sin theta - 15 Cos theta, in the format: R.Sin(theta + beta)
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document.write( "(b) Using your answer to part (a), solve; 8 Sin theta - 15 Cos theta=8.5 for 0degrees<=theta<=360degrees \n" );
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Algebra.Com's Answer #47034 by venugopalramana(3286) You can put this solution on YOUR website! (a) Express 8 Sin theta - 15 Cos theta, in the format: R.Sin(theta + beta) \n" ); document.write( "LET US USE T FOR THETA AND B FOR BETA \n" ); document.write( "DIVIDE AND MULTIPLY WITH SQRT(8^2+15^2)=17 \n" ); document.write( "PUT 8/17=COS(B)....THEN.....15/17=SIN(B)...SINCE SIN(B)=SQRT[1-COS^2(B) \n" ); document.write( "=SQRT[1-(8/17)^2]=15/17 \n" ); document.write( "HENCE WE GET \n" ); document.write( "8SIN(T)-15COS(B)=17[(8/17)SIN(T)-(15/17)COS(T)] \n" ); document.write( "=17[SIN(T)COS(B)-COS(T)SIN(B)]=17SIN[T-B].. \n" ); document.write( "HENCE R=17 AND B=ARCSIN(15/17) \n" ); document.write( "IF YOU WANT ONLY SIN (T+B)THEN YOU HAVE TO CHANGE THE QUADRANT \n" ); document.write( "FOR THE ANGLE FROM I Q AT PRESENT.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "(b) Using your answer to part (a), solve; 8 Sin theta - 15 Cos theta=8.5 for 0degrees<=theta<=360degrees \n" ); document.write( "WE HAVE \n" ); document.write( "17SIN(T-B)=8.5 \n" ); document.write( "SIN(T-B)=8.5/17=1/2=SIN(30)....OR....SIN(150).....OR...SIN(390)...ETC \n" ); document.write( "T-B=30....OR....150...OR....390...0R....510...ETC \n" ); document.write( "BUT B = ARCSIN(15/17)=62 DEG. \n" ); document.write( "T=92...OR.....212...IN THE DESIRED RANGE OF 0 \n" ); document.write( "T |