Can someone me the part c ? i don’t know why but i’m getting wrong answer! someone explain to me step by step!

So long as R1 is greater than 2, R will be greater than 1.

Step-by-step explanation:

Denote the three resistances as R, R1 and R2.

Then:

1        1           1

= +

 R      R1        R2

For now, substitute 1 for R and 2 for R2:

1        1           1

= +

 1      R1         2

Solve this for R1.  Notice that the LCD here is 2R1.

2R1 = 2 + R1, or R1 = 2.  Then we have

1        1           1

= + , which, as expected, yields R = 1.

 R       2         2

Next, determine the values of R resulting from choices of R1 smaller than 2 and greater than 2:

If R1  = 1.5 (that is, less than 2), then:

1        1           1          2 + 1.5       3.5                            3

= + =   = .  Thus, R = , which is less

 R      1.5         2            3              3                           3.5      than 1 and                          

                                                                                              therefore

                                                                                              unacceptable.

Next, let R1 = 2.1 (greater than 1):

1        1           1          2 + 2.1       4.1                          4.2

= + =   = .  Thus, R = , which is greater

 R      2.1         2            4.2          4.2                         4.1      than 1 and there-

                                                                                              fore acceptable.

Conclusion:  So long as R1 is greater than 2, R will be greater than 1.

can i see the following ?

step-by-step explanation:

the arc length is found by finding the circumference of the full circle (2xpixradius) and then dividing by 4 to find just one quarter of the circle (90 degrees).