What do we know about tan(x) and sec(x)? We know tan(x)=sin(x)cos(x),sec(x)=1cos(x). Now use these, and replace them in the equation.
We get sin(x)cos(x)+1cos(x)=0. Multiplying by cos(x), with the restriction, cos(x) is not equal to 0, gives us sin(x)+1=0, or sin(x)=−1. So, now we use the formula, sin2(x)+cos2(x)=1, we get cos2(x)=0,cos(x)=0. Notice there is only one solution, because +/- 0 is always 0.
But we see from ealier that cos(x) is not 0, so we have no solution.
What do we know about tan(x) and sec(x)? We know tan(x)=sin(x)cos(x),sec(x)=1cos(x). Now use these, and replace them in the equation.
We get sin(x)cos(x)+1cos(x)=0. Multiplying by cos(x), with the restriction, cos(x) is not equal to 0, gives us sin(x)+1=0, or sin(x)=−1. So, now we use the formula, sin2(x)+cos2(x)=1, we get cos2(x)=0,cos(x)=0. Notice there is only one solution, because +/- 0 is always 0.
But we see from ealier that cos(x) is not 0, so we have no solution.