integre 1/cos(x)^2
Let's integrate: <math><mo>∫(</mo><mfrac><mrow><mn>1</mn></mrow><mrow><msup><mrow><mi>cos</mi><mo>(</mo><mi>x</mi><mo>)</mo></mrow><mrow><mn>2</mn></mrow></msup></mrow></mfrac><mo>)dx</mo></math>
 <math><mi>tan</mi><mo>(</mo><mi>x</mi><mo>)</mo></math>
Indefinite integrals are defined up to an additive constant <m>C</m>, so this yields: <math><mi>tan</mi><mo>(</mo><mi>x</mi><mo>)</mo><mo> + </mo><mi>C</mi></math>

▷<b>Result: &nbsp; <math><mi>tan</mi><mo>(</mo><mi>x</mi><mo>)</mo><mo> + </mo><mi>C</mi></math></b><span style='font-size:smaller'>, with <m>C</m> being any constant &nbsp; &nbsp; (computation took 3 steps and 1 ms)</span>