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4 years ago

David determine 80% of 10% he got 80 what he do wrong

Mathematics

1 answer:

lutik1710 [3]4 years ago

3 0

80% of 10% = 0.8 x 10% = 8%

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(sinA-cosA+1)/(sinA+cosA-1)=2(1+cosecA)

borishaifa [10]

Answer:

The trigonometrical expression is sin² A + sin A - 2 cos A - 2 cos A × sin A = 0

Step-by-step explanation:

Given Trigonometrical function as :

$\frac{sin A - cos A + 1}{sin A + cos A - 1}$ = 2 (1 + cosec A)

Or, $\frac{sin A + ( 1 - cos A)}{sin A - (1 - cos A)}$ = 2 (1 + cosec A)

, Now, rationalizing

$\frac{(sin A + ( 1 - cos A)) \times (sin A + (1 - cosA))}{(sin A - (1 - cos A))\times (sin A + (1 - cos A))}$ = 2 (1 + cosec A)

Or, $\frac{(sin A + (1 - cos A))^{2}}{sin^{2} - (1-cos A)^{2}}$ = 2 ( 1 + $\dfrac{1}{\textrm sinA}$

Or, $\frac{sin^{2}A + (1 - cosA)^{2} + 2 \times sin A \times (1 - cos A)}{sin^{2}A - (1 + cos^{2}A - 2 cos A)}$ = 2 ( $\dfrac{1 + sin A}{sin A}$

Or, $\frac{sin^{2}A + 1 + cos^{2}A - 2 cos A + 2 sin A - 2 sin A cos A}{sin^{2}A - 1 - cos^{2}A +2 cos A}$ = 2 ( $\dfrac{1 + sin A}{sin A}$

Or, $\frac{sin^{2}A + 1 + cos^{2}A - 2 cos A + 2 sin A - 2 sin A cos A}{sin^{2}A - (sin^{2}A + cos^{2}A) - cos^{2}A +2 cos A}$ = 2 ( $\dfrac{1 + sin A}{sin A}$

Or, $\frac{2- 2 cos A + 2 sin A - 2 sin A cos A}{- 2cos^{2}A +2 cos A}$ = 2 ( $\dfrac{1 + sin A}{sin A}$

Or, $\frac{1- cos A + sin A - sin A cos A}{- cos^{2}A + cos A}$ = 2 ( $\dfrac{1 + sin A}{sin A}$

Or, $\frac{(1- cos A) + sin A (1-cos A)}{cos A(1 - cos A)}$ = 2 ( $\dfrac{1 + sin A}{sin A}$

Or, $\frac{(1- cos A) (1 + sinA)}{cos A(1 - cos A)}$ = 2 ( $\dfrac{1 + sin A}{sin A}$

Or, $\frac{(1 + sinA)}{(cos A)}$ = 2 ( $\dfrac{1 + sin A}{sin A}$

Or, sin A + sin² A = 2 cos A (1 + sin A)

Or, sin A + sin² A = 2 cos A + 2 cos A × sin A

Or, sin² A + sin A - 2 cos A - 2 cos A × sin A = 0

So,The trigonometrical expression is sin² A + sin A - 2 cos A - 2 cos A × sin A = 0 Answer

6 0

3 years ago

Solve each calculation. Be sure to report your answer with the correct number of significant figures.

Serjik [45]

Question:

Solve each calculation. Be sure to report your answer with the correct number of significant figures.

5.61000 dg × 1.1010 dg

12.0 m ÷ 3.1415 m

Answer:

1. $5.61000dg * 1.1010dg$ = $6.177 dg^2$

2. $\frac{12}{3.1415} = 3.8198$

Step-by-step explanation:

1. 5.61000 dg × 1.1010 dg

We start by representing each digit using scientific notation

$5.61000 = 561000 * 10^{-5}$

$1.1010 = 11010 * 10^{-4}$

Then, Multiply both numbers

$561000 * 10^{-5} * 11010 * 10^{-4}$

First, rearrange

$561000 * 11010 * 10^{-5} * 10^{-4}$

$6176610000 * 10^{-5} * 10^{-4}$

From law of indices, $10^{-5} * 10^{-4} = 10^{-9}$ ;

So, we have

$6176610000 * 10^{-9}$

$6.176610000$

Because 5.61000 is given in 3 significant figures and 1.1010 is given in 4 significant figures, we approximate the result to 4 significant figures

This gives $6.177$