Y ' = (tgx) ' = 1/cos^2x
y ' = (1/cos^2x) = (cos^(-2)x)' = - 2 cos^(-3)x * ( - sinx) = 2tgx *1/cos^2x
<span>-15(4y-3)+37y=42y-111</span>
<span>-60у+45+37у=42у-111</span>
<span>-23у-42у=-111-45</span>
<span>-65у=-156</span>
<span>у=-156:(-65)</span>
<span>у=2,4</span>