Question

URGENTE
Sabendo que tg x = a+3 e que sec² x = a+16, determine o(s) valor(se) de a.

Answer 1

sec^2(x) -tg^2(x)=1
a+16-(a+3)^2 =1
a+16 -(a^2 +2*3a +3^2)=1
a+16 -a^2 -6a -9=1
-a^2 -5a +7=1
-a^2 -5a+6=0*(-1)
a^2 +5a-6=0

delta=b^2 -4ac=5^2 -4*1*-6=25+24=49
delta^(1/2)=7

a1=-b+7/2a=-5+7/2=2/2=1
a2=-5-7/2=-12/2=-6