1. Create a Fast PWM signal of 1Hz frequency. In the 1st cycle, the duty cycle will be 10%, in the 2nd cycle, the duty cycle will be 20%. Like this, the duty cycle will keep on increasing by 10% in every cycle until it reaches 100%. Then, in the next cycle, the duty cycle will be 90%. In the following cycles, the duty cycle will keep on decreasing by 10% in every cycle until it reaches 10%. After reaching 10%, the whole process will keep on repeating. 2. analogWrite(9,127) function will create a PWM signal of 490Hz with 50% duty cycle at DPin-9 and analogWrite (5,127 ) function will create a PWM signal of 980Hz with 50% duty cycle at DPin5. But it can't be visualized. So, using these signals as IRQ0 and IRQ1, their time period can be detected. From that, the frequency can be calculated. (Hints: Use trigger level as RISING or FALLING at INT0 and INT1.)