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Junior high school mathematics moving point topic
Solution: (1)∫ In the rectangular ABdD, AB=6dm, Bd=8dm,

According to Pythagorean theorem, AC=x0cm,

The time of exercise is t seconds (1 < x < 5).

∴AP=2tcm,CQ=tcm,

CP=( 10-2t)cm。

QE⊥AC with point Q as point E.

∠∠QEC =∠B = 90,∠ACB=∠ACB,

∴△QEC∽△ABC,

QE

ab blood type

=

Charge of quarters

Canada

QE

six

=

t

10

,∴QE=

three

five

t

The functional relationship between s and t is:

S=

1

2

PC? QE=

1

2

( 10-0t)?

three

o

t=-

three

five

t2+3t。

A: The functional relationship between S and T is S=-

three

five

t2+3t。

(2) Solution: ∫S =-

three

u

(t-

five

2

)2+

1

four

∴t=

five

2

S, △PwC has the largest area, and the largest area is

1j

four

tm2,

A: When T is

five

z

S, △oQw has the largest area, and the largest area is

15

f

Square centimeters.

(3) During the movement of P and Q, △PQC can be a right triangle.

There are two situations:

① when PQC = 1L,

∫△6PQ∽△6AB,

Charge of quarters

Civil band

=

cerebral palsy

Canada

1h-2 1

10

=

t

eight

Solve t=

40

13

< 5 fits the question.

② When ∠ CPQ = 90,

∫△0PQ∽△00A,

cerebral palsy

Civil band

=

Charge of quarters

Canada

1b-2t

eight

=

t

10

Solve t=

25

seven

< 5 fits the question.

To sum up, during the movement of P and Q,

while

40

13

S or

25

seven

S, △PQC can be a right triangle. A: During the movement of P and Q, △PQC can be a right triangle, and the value of T is

40

13

S or

25

seven

south

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