Answer:
D
Step-by-step explanation:
i think it's correct if not I'm sorry
Answer:
Step-by-step explanation:
Given the expression cosec (x) = 4 and tan(x)< 0
since cosec x = 1/sinx
1/sinx = 4
sinx = 1/4
From SOH, CAH TOA
sinθ = opposite/hypotenuse
from sinx = 1/4
opposite = 1 and hypotenuse = 4
to get the adjacent, we will use the Pythagoras theorem
adj² = 4²-1²
adj² = 16-1
adj ²= 15
adj = √15
cosx = adj/hyp = √15/4
tanx = opposite/adjacent = 1/√15
since tan < 0, then tanx = -1/√15
From double angle formula;
sin2x = 2sinxcosx
sin2x = 2(1/4)(√15/4)
sin2x = 2√15/16
sin2x = √15/8
for cos2x;
cos2x = 1-2sin²x
cos2x = 1-2(1/4)²
cos2x = 1-2(1/16)
cos2x= 1-1/8
cos2x = 7/8
for tan2x;
tan2x = tanx + tanx/1-tan²x
tan2x = 2tanx/1-tan²x
tan2x = 2(-1/√15)/1-(-1/√15)²
tan2x = (-2/√15)/(1-1/15)
tan2x = (-2/√15)/(14/15)
tan2x = -2/√15 * 15/14
tan2x = -30/14√15
tan2x = -30/7√15
rationalize
tan2x = -30/7√15 * √15/√15
tan2x = -30√15/7*15
tan2x = -2√15/7
Answer:
Length = 9units
Width = 7units
Step-by-step explanation:
It is said that the length is 2units more than the width
Assume that the width is x, then the length will be 2 + x
ie
Width = x
Length = 2 + x
Area of the rectangle = 63units
Area of rectangle = l * b
l - length of the rectangle
b - width of the rectangle
A = l * b
63 = (2 + x) * x
63 = ( 2 + x) x
63 = 2x + x^2
Let's rearrange it
x^2 + 2x - 63 = 0
Let's find the factor of 63
A factor that can be multiplied to give -63 and that can be added to give +2
Let's use -7 and +9
x^2 - 7x + 9x - 63 = 0
Separate with brackets
( x^2 - 7x) + ( 9x - 63) = 0
x( x - 7) + 9(x - 7) = 0
( x + 9)(x - 7) = 0
( x + 9) = 0
( x - 7) = 0
x + 9 = 0
x = -9
x - 7 = 0
x = 7
Note: the length of a rectangle can not be negative
So therefore,
x = 7
Length = 2 + x
= 2 + 7
= 9units
Width = x
= 7units
Account balance is $123.08
Step-by-step explanation:
- Step 1: Balance in Thompson's account = $283.12. Calculate the total amount of checks Thompson wrote in the month.
Total amount of checks = $23.09 + $7.56 + $125.11 + $4.28
= $160.04
- Step 2: Calculate his balance.
Account balance = $283.12 - $160.04
= $123.08
