## Όλα τα έργα

#### [MOOC]Redução ao primeiro quadrante e fórmulas trigonométricas

Seja $\alpha \in \left [ \frac{\pi }{2}, \frac{3\pi }{2} \right ]$, tal que $sen\alpha =\frac{\sqrt{5}}{5}$ Determina o valor de $tg\left ( \pi +\alpha \right )\times cos\left ( \frac{11\pi }{2}+\alpha \right )+sen\left ( -\frac{\pi }{2}-\alpha \right )$. Apresenta o resultado arredondado às centésimas.

# Trigonometric functions

Reasoning
11

#### Right Triangle

Calculate the missing value.

# Pythagorean theorem

Learning
8

#### Finding out the hypotenuse

Calculate the exact value of the missing value. Select the true statements.

# Pythagorean theorem

Training
8

#### Calculate abscissa with Pythagorean Theorem

Calculate the exact value of abscissa of point $\ {A}$.

# Pythagorean theorem

Learning
8

#### Lake modeling

In a lake, there are p fish. For each fish there are 20 fish eggs. Among the 20 fish eggs, just 7 hatch for each fish. Can you tell how many fish will be in the lake once the eggs hatch?

# Terms with variables

Modeling
7

#### Supportive task for "From natural to algebraic language"

How can we express with symbols an even and an odd number respectively?

# Natural numbers

Training
8