A little math problem, a little math problem to solve

If the function y=(m+1)x+3 passes through the point (1,2), then m=?x=1, y=2 substitution:

2=(m+1)*1+3, so m= -2.

What is the range of the value of the independent variable x in the function y = root number (x-5)?

The square of both sides, y 2 = x-5, because y 2> = 0, so x-5 > muffled loss = 0, that is, x> = 5

If you don't score, you don't have empty hands.

Because d is the dim sum in ao, do=ao 2=5 When the triangle ODP is an isosceles triangle, p is obviously not in line with the topic above the midpoint of do, so there is only:

It only makes sense when op=od, but od=5

Let the p point be (x,4).

op²=4²+x²=25

This yields x=3, (negative root rounded).

So when the triangle ODP is an isosceles triangle with a waist length of 5, the coordinates of the point p are (3,4).

The factor of 6 is , and the factor of 9 is

The factor of 15 is , and the factor of 12 is

The factor of 42 is , and the factor of 54 is

The factor of 30 is , and the factor of 45 is

The factor of 99 is , and the factor of 36 is

The factor of 5 is the factor of 9

The factor of 34 is , and the factor of 17 is

From the Pythagorean theorem there is BC= (ab2-AC2)= (8 2-4 2)=4 3

Let the distance from the center of the circle c to ab be (1 2)ac*bc=(1 2)ab*d by the triangle area formula

That is, (1 2)*4*4 3=(1 2)*8*d solution gives d=2 3

That is, a circle with a radius of 3 is separated from ab, a circle with a radius of 5 intersects with ab, and a circle is tangent to ab when the radius is equal to 2 3.

From the Pythagorean theorem, another right-angled side BC=4 3, because the hypotenuse AB of RT ABC is 8cm, and the right-angled side AC is 4cm, so B=30°, and the high CD of the hypotenuse AB is CD=(1 2)BC=2 3, so when the radius is 3cm, it intersects when it is 5cm, and it is tangent when it is equal to 2 3.

The train not only has to cross the 1200-meter-long bridge, but also makes its own 90 meters pass, so the total length of travel is 1200+90, know the speed, find the time.

Column: (1200+90) 30

43（s)

Columnar answer: (1200+90) 30

43(s) If you don't understand, you can ask again, thank you.

The area is the base multiplied by the height divided by 2, and what to consider is when the p point moves to the curve!! At that time, x times y divided by 2In fact, it is equal to !!

So at the beginning, it slowly gets bigger, because its base and height get bigger at the same time, so this is not a fixed multiplier that gets bigger, it's two variables that get bigger at the same time, and the image of this function is a curve, and it's increasing upwards. Then when p is on the curve, it is a fixed value, as long as p is still on the curve, it is a fixed value, that is!! After b, because the base keeps getting smaller, and the height doesn't change, the area keeps getting smaller, but only one variable changes, so the function image is a straight line function image.

to c, it is 0

A should be chosen.