document.write( "Question 789386: I have 2 questions\"\r
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document.write( "1)Find all values of θ that satisfy the equation over the interval [0, 2π].
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document.write( "cos theta = sin theta. Please help me solve this problem. I do not know where to begin. I looked through some notes and tried a few answers and they are not coming out correct. The question asks that I give the smaller and larger values in rad.
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document.write( "2)And the second is given cos theta= 7/8. Find the other 5 trig functions of theta. I found sec theta as 8/7. but how would I use those 2 to find the other 4 functions? \r
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document.write( "Thank you for your help,\r
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document.write( "Jolene \n" );
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Algebra.Com's Answer #478855 by rothauserc(4718)![]() ![]() You can put this solution on YOUR website! note that pi in trig equals 180 degrees so problem 1 is asking for all values from 0 to 360 degrees where cos theta = sin theta which covers all four quadrants \n" ); document.write( "1) here we go :-) \n" ); document.write( "cos theta = sin theta implies cos theta equals cos (pi/2 - theta), this implies that theta = 2n*pi + (pi/2 - theta) where n is 0, 1, 2, 3, 4, ....., so 2*theta = 2n*pi +pi/2 implies theta = n*pi + pi/4 , which satisfies the relation \n" ); document.write( "we see that cos theta = sin theta for theta = 45 or 225 degrees \n" ); document.write( "now convert these angles to radians by multiplying degrees by pi/180 \n" ); document.write( "therefore we have pi/4 and 5*pi/4 \n" ); document.write( "2)we are given cos theta = 7/8 \n" ); document.write( "using the relation a^2 + b^2 = c^2 we get \n" ); document.write( "a^2 + 7^2 = 8^2 \n" ); document.write( "a^2 = 64 -49 = 15 \n" ); document.write( "a = 3.8 \n" ); document.write( "from this we have \n" ); document.write( "sin = 3.8 / 8 \n" ); document.write( "cos = 7 / 8 \n" ); document.write( "tan = 3.8 / 7 \n" ); document.write( "csc = 8 / 3.8 \n" ); document.write( "sec = 8 / 7 \n" ); document.write( "cot = 7 / 3.8\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |