Question

Помогите пожалуйста !!

Answer 1

Ответ:

$A6)\; \; 6\, ctga+3\, ctga\cdot cosa-4cosa-8=0\\\\3ctga\cdot (2+cosa)-4(cosa+2)=0\\\\(2+cosa)\cdot (3\, ctga-4)=0\; \; \Rightarrow \; \; \left [ {{2+cosa=0} \atop {3\, ctga-4=0}} \right. \; \; \left [ {{a\in \varnothing } \atop {ctga=\frac{4}{3}}} \right. \\\\ctga=1\frac{1}{3}\\\\Otvet:\; \; \#4\; .$

$A8)\; \; f(x)\geq 0\; \; \; pri\; \; \; x\in [-\frac{\pi }{2}\, ,\, \frac{\pi }{2}\; ]\\\\\\Otvet:\; \; \#4\; .\\\\A9)\; \; y=2,5^{0,5x}+1\\\\\star \; \; a^{x}>0\; \; \; pri\; \; \; x\in (-\infty ,+\infty )\; \; \star \\\\2,5^{0,5x}>0\\\\2,5^{0,5x}+1>0+1\\\\2,5^{0,5x}+1>1\; \; \Rightarrow \; \; \; 1<(2,5^{0,5x}+1)<+\infty \; \; ,\; \; E(y)=(1,+\infty )\\\\42>1\\\\42\in E(y)\\\\Otvet:\; \; \#1\; .$