Evaluate the following indefinite integral on \( \left(-\frac{\pi}2,\frac{\pi}2 \right) \).
\[ \int \left(\frac1{\cos x}-\sin x\cdot\mathrm{tg}\,x\right)\,\mathrm{d}x \]
The production process of a particular component consists of three independent phases.
Through long-term monitoring of production quality were found success rates of individual phases \( 90\% \), \( 80\% \) and \( 85\% \). If all three phases of the process are successful, the component is of good quality. What is the probability of producing a good quality component?
The probability of a man hitting a target is \( 0{.}9 \). What is the probability that he hits the target twice in a row? Round the result to two decimal places.
The quality inspection found that \( 85\% \) of the items are without defect, exactly one defect has \( 10\% \) of the items, and the other items have more than one defect. We pick one item randomly. What is the probability that this item has at least one defect?