Answer:
0.761
Step-by-step explanation:the 7 is in the tenths the 6 is in the hundredths and the 1 is in the thousandths
If period of

is one-half the period of

and
<span>

has a period of 2π, then

and

.
</span>
To find the period of sine function

we use the rule

.
<span /><span />
f is sine function where f (0)=0, then c=0; with period

, then

, because

.
To find a we consider the condition

, from where

.
If the amplitude of

is twice the amplitude of

, then

has a product factor twice smaller than

and while period of

<span> </span> is 2π and g(0)=0, we can write

.
Cosα=x/L
L=x/cosα, we are told that the ladder base is 48 ft from the base of the wall and α=39° so:
L=48/cos39 ft
L≈61.76 ft (to nearest hundredth of a foot)