4^x+4^x+1<80
4^x+4^x×4<80
5×4^x<80
4^x<80÷5
4^x<16
4^x<4^2
x<2
sin^2-1/1-cos^a=-cos^2a/sin^2a=-ctg^2a
4^x+4^x+1<80
4^x+4^x×4<80
5×4^x<80
4^x<80÷5
4^x<16
4^x<4^2
x<2
sin^2-1/1-cos^a=-cos^2a/sin^2a=-ctg^2a