2 years ago

If cosA = 3/5 and A ∈ (630,720), find sin2A

Mathematics

1 answer:

Sergio039 [100]2 years ago

5 0

Answer:

- $\frac{24}{25}$

Step-by-step explanation:

Given 630 < A > 720 then A is in the fourth quadrant where

cosA > 0 and sinA < 0

Given

cosA = $\frac{3}{5}$ = $\frac{adjacent}{hypotenuse}$

Then the triangle is a 3- 4 - 5 with opposite side 4, thus

sinA = - $\frac{opposite}{hypotenuse}$ = - $\frac{4}{5}$

Using the trigonometric identity

sin2A = 2sinAcosA

= 2 × - $\frac{4}{5}$ × $\frac{3}{5}$

= $\frac{2(-4)(3)}{5(5)}$ = - $\frac{24}{25}$

You might be interested in

At a cafe , the cook uses a recipe that calls for eggs and milk have a proportional relationship. Complete the table.

SVEN [57.7K]

Answer:

Milk over eggs is gonna be 3 over 1

Step-by-step explanation:

7 0

2 years ago

Read 2 more answers

The medians $AD$, $BE$, and $CF$ of triangle $ABC$ intersect at the centroid $G$. The line through $G$ that is parallel to $BC$

Flauer [41]

G divides each median in the ratio of 2 to 1 (the longer side goes from G to the angle) triangle AMN is similar to triangle ABC (why?) AMN is a scaled version of ABC (by a factor of ⅔) its area should be scaled by (⅔)^2

6 0

2 years ago

Solve for n 20 > -4x - 8

LekaFEV [45]

The answer is X>-7 for your question

5 0

2 years ago

The probability that a train leaves on time is 0.9. The probability that the train arrives on time and leaves on time is 0.36. W

ASHA 777 [7]

P(arrives on time given leaves on time)=
P(B | A)= P(B n A) / P(A)
= P(A n B) / P(A)
= 0.36 / 0.9
= 0.4

5 0

2 years ago

Read 2 more answers

Which equation is equivalent to 3x=33

Lena [83]

X=11 is the answer right?

6 0

2 years ago