Question

ex 9 e si f va rog ​

Answer 1

Răspuns:

Explicație pas cu pas:

e)  (2x+1)(3-x)>0    x²+4>0  oricare ar fi x   deci nu va conta la semnul expresiei

x..........................-1/2...................................3.............

2x+1 ----------------0+++++++++++++++++++++++++++

3-x+++++++++++++++++++++++++++++0---------------

f(x)-------------------0++++++++++++++++0----------------

x∈(-1/2,3)

f) x²-x-2=(x+1)(x-2)

x......................-1.........0..................2................

x+1--------------0+++++++++++++++++++++++++

x-2--------------------------------------0++++++++++++++

x---------------------------0+++++++++++++++++++++++++

f(x)--------------0+++++I--------------0++++++++++++++++

x∈(-∞,-1]∪(0,2]