Question

Doar cele incercuite. Multumesc !

Answer 1

subiectul1(varianta13)
3(4-√3)+3√3=12
12-3√3+3√3=12
12=12  (A)

2)f(-4)+f(4)
f(x)=x²-16

f(-4)=(-4)²-16=16-16=0
f(4)=(4)²-16=16-16=0
f(-4)+f(4)=0+0=0

3)(x-2)²-x²+8=0⇒x²-4x+4-x²+8=0⇒-4x+12=0⇒-4x=-12⇒x=-12/-4⇒x=3,,x∈R

4)100X30/100=30
100-30=70 PRET FINAL

5)A(2.4).
   B(2.1)
AB=√(XB-XA)²+(YB-YA)²=
AB=√(2-2)²+(1-4)²⇒
AB=√0²+(-3)²⇒AB=√0+9⇒AB=√9⇒AB=3

6)Cos A =?

Sin A=1/2
∡A=ascutit
cosA=+-√1-sin(1/2)²⇒+-√1-1/4⇒+-√4-1/4⇒+-√3/4⇒+√3/2(1)
cos A=∡90
Cos A=∡ascutit(2)
din (1)si (2)⇒cos A=√3/2
SUCCES