indu1954 wrote:
Topic-Function
In the coordinate plane there is the area of the region shaded surrounded by 3 inequalities. Which of the following options can be these inequalities?
1) x>0 2) y>0 3) y<-3x+8 4) y>(1/2)x+4 5) y>(-1/2)x+4
A. 1), 3), 5) B. 1), 3), 4) C. 2), 3), 5) D. 2), 3), 4) E. 2), 4), 5)
Hi..
In very simple terms,
You should note that the area is surrounded by three straight lines..
So if you substitute the inequality sign(< and >) with equality sign (=) in all 5 options, you should be able to get equation of these lines....
The next thing you can say that the two lines apart from y axis are having negative slope, because y and x have opposite effects, one increases the other decreases.
So the options that have negative coefficient of X while positive of y can be the equation of line..
Choice 3 and 5 have negative slope given by coefficients of x, -3 and -1/2.
Now we are left with the third side ..
So on y_axis, X is always 0, so x=0 is the third side, so 1,3,5
A
Of course if you want to get a bit more on theory , you can decide on the inequality sign < and > in option 3 and 5. But here you can answer without getting into any other details
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