document.write( "Question 441508: Use the Quadratic Formula to solve the equation in the interval
\n" ); document.write( "[0, 2π). (Round your answers to four decimal places.)
\n" ); document.write( "4 tan2 x + 15 tan x − 25 = 0 \n" ); document.write( "
Algebra.Com's Answer #306448 by lwsshak3(11628)\"\" \"About 
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Use the Quadratic Formula to solve the equation in the interval
\n" ); document.write( "[0, 2π). (Round your answers to four decimal places.)
\n" ); document.write( "4 tan2 x + 15 tan x − 25 = 0
\n" ); document.write( "..
\n" ); document.write( "I will assume the first term is 4 tan^2x instead of 4 tanx as given
\n" ); document.write( "4 tan^2 x + 15 tan x − 25 = 0
\n" ); document.write( "a=4, b=15, c=-25
\n" ); document.write( "tanx=[-15+-sqrt(15^2-4*4*-25)]/2*4
\n" ); document.write( " =[-15+-sqrt(625)]/8
\n" ); document.write( " =(-15+-25)/8
\n" ); document.write( " =-40/8 or 10/8
\n" ); document.write( " =-5 or 1.25
\n" ); document.write( "using inverse function key for tan
\n" ); document.write( "tanx=-5
\n" ); document.write( "x=101.3099º (note that calculator will give a reference angle of -78.6900º, but this is not within specified domain for x, hence the angle must be in quadrant II where tan x is also negative)
\n" ); document.write( "tanx=1.25
\n" ); document.write( "x=51.3402º
\n" ); document.write( "ans:
\n" ); document.write( "x=101.3099º and 51.3402º in domain[0,2π) \n" ); document.write( "
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