Răspuns:
a) = 0
b) = [tex]\frac{1}{sin^3^6^0}[/tex]
Explicație pas cu pas:
[tex]a) \frac{sin\pi }{11} +\frac{sin\pi }{7} -\frac{sin6\pi }{7} -\frac{sin10\pi }{y}= \frac{sin\pi-sin10\pi }{11} +\frac{sin\pi-sin6\pi }{7}[/tex], amplificam prima fractie cu 7, iar pe a doua cu 11; [tex]\frac{(sin\pi-sin10\pi)*7 }{77}+\frac{(sin\pi-sin6\pi )*11 }{77} =\frac{0}{77} +\frac{0}{77} =\frac{0}{77} =0[/tex]
[tex]b) \frac{sin^7^0+sin^4^0}{sin^2^5^0+sin^2^2^0} =\frac{sin^1^1^0}{sin^4^7^0} =sin^1^1^0^-^4^7^0=sin^-^3^6^0=\frac{1}{sin^3^6^0}[/tex]
