Question

va rog am nevoie de 4 si 5 urgent explicatie pas cu pas dau coroana si multe puncte ​

Answer 1

4) t=√[a(a+2)(a+4)(a+6)+16]

notam b=a+3

=> a(a+2)(a+4)(a+6)=(b-3)(b-1)(b+1)(b+3)

=(b²-1)(b²-9)

=b^4-10b²+9

=> t=√( b^4-10b²+9+16)

t=√( b^4-10b²+25)= =√( b²-5)²

t= b²-5 ; t=(a+3)²-5

t=a²+6a+9-5

t=a²+6a+4; t∈Q

5 )m(<BAC)=90; AC=6 cm; ctg(<ACB)=1/7

a) ctg(<ACB)=AC/AB=1/7

=> AB=7AC=42 cm

BC²= AB²+ AC²=(1764+36)cm²=1800cm²

BC=30√2  cm

b) A ΔABC=AB•AC/2=42cm•6cm/2=126cm²